I've managed to fix it by manually removing openfl from the lib directory and installing using haxelib install openfl. I can now run windows target, but html5 is a big no no.
C:/HaxeToolkit/haxe/lib/lime/2,4,4/lime/system/System.hx:103: characters 2-24 : Class<ApplicationMain> has no field create
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:98: characters 17-30 : Array<openfl.display.DisplayObject> should be Array<flash.display.DisplayObject>
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:98: characters 17-30 : Type parameters are invariant
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:98: characters 17-30 : openfl.display.DisplayObject should be flash.display.DisplayObject
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:98: characters 17-30 : For function argument 'h'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:99: characters 14-33 : flash.display.InteractiveObject should be openfl.display.DisplayObject
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:101: characters 34-75 : flash.events.MouseEvent should be openfl.events.Event
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:101: characters 34-75 : For function argument 'event'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:102: characters 34-76 : flash.events.MouseEvent should be openfl.events.Event
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:102: characters 34-76 : For function argument 'event'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:108: characters 17-30 : Array<openfl.display.DisplayObject> should be Array<flash.display.DisplayObject>
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:108: characters 17-30 : Type parameters are invariant
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:108: characters 17-30 : openfl.display.DisplayObject should be flash.display.DisplayObject
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:108: characters 17-30 : For function argument 'h'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:278: characters 35-43 : flash.geom.Point should be openfl.geom.Point
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:278: characters 35-43 : For function argument 'pos'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:300: characters 49-57 : flash.geom.Point should be openfl.geom.Point
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Stage.hx:300: characters 49-57 : For function argument 'pos'
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:25: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:25: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:25: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:25: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:25: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:165: characters 9-40 : openfl.display.BitmapData should be flash.display.BitmapData
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxAssets.hx:176: characters 9-40 : openfl.media.Sound should be flash.media.Sound
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/frontEnds/SoundFrontEnd.hx:144: characters 3-52 : openfl.media.Sound should be flash.media.Sound
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/FlxSprite.hx:29: characters 8-50 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/FlxSprite.hx:29: characters 8-50 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/FlxSprite.hx:29: characters 8-50 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/FlxSprite.hx:29: characters 8-50 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/FlxSprite.hx:29: characters 8-50 : Defined in this class
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:22: characters 8-14 : flash.display.BitmapData should be openfl.display.BitmapData
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:22: characters 8-14 : For function argument 'image'
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:20: lines 20-26 : Missing super constructor call
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:34: characters 15-27 : flash.geom.Rectangle should be openfl.geom.Rectangle
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:34: characters 15-27 : For function argument 'rectangle'
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:75: characters 14-18 : flash.geom.Rectangle should be openfl.geom.Rectangle
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/layer/TileSheetExt.hx:75: characters 14-18 : For function argument 'rectangle'
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:29: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:29: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:29: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:29: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:29: characters 0-39 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:32: characters 0-42 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:32: characters 0-42 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:32: characters 0-42 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:32: characters 0-42 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/tile/FlxTilemap.hx:32: characters 0-42 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:20: characters 8-55 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:20: characters 8-55 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:20: characters 8-55 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:20: characters 8-55 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:20: characters 8-55 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:23: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:23: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:23: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:23: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/debug/Window.hx:23: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxSound.hx:282: characters 3-42 : openfl.media.Sound should be flash.media.Sound
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/input/mouse/FlxMouse.hx:28: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/input/mouse/FlxMouse.hx:28: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/input/mouse/FlxMouse.hx:28: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/input/mouse/FlxMouse.hx:28: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/input/mouse/FlxMouse.hx:28: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/frontEnds/SoundFrontEnd.hx:170: characters 3-41 : openfl.media.Sound should be flash.media.Sound
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/ui/FlxTypedButton.hx:14: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/ui/FlxTypedButton.hx:14: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/ui/FlxTypedButton.hx:14: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/ui/FlxTypedButton.hx:14: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/ui/FlxTypedButton.hx:14: characters 8-49 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:19: characters 8-52 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:19: characters 8-52 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:19: characters 8-52 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:19: characters 8-52 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:19: characters 8-52 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:22: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1161: characters 5-12 : Invalid assign
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:22: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1162: characters 13-26 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:22: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1163: characters 14-28 : Unknown identifier : __image
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:22: characters 8-54 : Defined in this class
C:/HaxeToolkit/haxe/lib/openfl/3,1,0/openfl/Assets.hx:1167: characters 5-17 : Unknown identifier : __fromBase64
C:/HaxeToolkit/haxe/lib/flixel/3,3,8/flixel/system/FlxPreloader.hx:22: characters 8-54 : Defined in this class
export/html5/haxe/ApplicationMain.hx:68: characters 23-67 : flixel.system.FlxPreloader should be flash.display.DisplayObject
export/html5/haxe/ApplicationMain.hx:68: characters 23-67 : For function argument 'o'
export/html5/haxe/ApplicationMain.hx:584: characters 26-35 : flixel.system.FlxPreloader should be flash.display.DisplayObject
export/html5/haxe/ApplicationMain.hx:584: characters 26-35 : For function argument 'o'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Sprite.hx:41: characters 39-43 : flash.display.Sprite should be openfl.display.DisplayObject
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Sprite.hx:41: characters 39-43 : For function argument 'o'
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Sprite.hx:45: characters 38-42 : flash.display.Sprite should be openfl.display.DisplayObject
C:/HaxeToolkit/haxe/lib/openfl-bitfive/3,0,0/flash/display/Sprite.hx:45: characters 38-42 : For function argument 'o'
export/html5/haxe/DefaultAssetLibrary.hx:430: lines 430-442 : Field exists overloads parent class with different or incomplete type
export/html5/haxe/DefaultAssetLibrary.hx:430: lines 430-442 : id : String -> t : openfl.AssetType -> Bool should be id : String -> type : String -> Bool
export/html5/haxe/DefaultAssetLibrary.hx:430: lines 430-442 : openfl.AssetType should be String
export/html5/haxe/DefaultAssetLibrary.hx:444: lines 444-448 : Field getBitmapData is declared 'override' but doesn't override any field
export/html5/haxe/DefaultAssetLibrary.hx:491: lines 491-497 : Field list overloads parent class with different or incomplete type
export/html5/haxe/DefaultAssetLibrary.hx:491: lines 491-497 : t : openfl.AssetType -> Array<String> should be type : String -> Array<String>
export/html5/haxe/DefaultAssetLibrary.hx:491: lines 491-497 : openfl.AssetType should be String
export/html5/haxe/DefaultAssetLibrary.hx:499: lines 499-512 : Field loadBitmapData is declared 'override' but doesn't override any field
Build halted with errors.