The play button is very close to the "create new file" button.

[felipe ruckert]

One thing that really bothered me when using the app was the proximity of the "create new project" button to the "play simulation" button. Seve
ral times when trying to run my simulation, I created a new project and lost my progress.

[Harry King]

You don't lose your progress if you accidentally click the New button. Multiple models can be open simultaneously in the software. Click on the Window button to view the open models and then select the one to display.

Harry