Hi Cesar,
You may already know this, but I won’t assume. The Game of Transformations, for developing phonemic awareness, has 4 rules: To transform one word into another one, one step at a time, where each change also creates a word, you can
1 add a sound/letter
2 substitute one sound/letter for another
3 reverse the whole word
4 insert a sound/letter into the word
So with the device you have shown, one student might present a starting word and then, having checked the feasibility of the transformation, challenge the other student to transform it into the target word.
For example:
in English
man. stamps
man map lap lamp tamp stamp stamps
and in Spanish
los somos
Los nos son sono solo solos somos
(Pardon my imperfect Spanish if I have made mistakes here.)
This is one pathway. There could be others.