here's some ideas

quiz
4/10
quiz
depending on how many questions you want
1 question i think is about 10-15 minuets. only if you can't come up with a question.

noise maker
3/10: only if recording is a pest
sound making game
also depending if you do too much code but if it has 3 sounds i reckon 5-12 minuets.

really hope this was helpful leahcimto