I know this is not the best place where I can ask a question, since this is not really a rant but I would really appreciate it if you can help me.

I was wondering if you can suggest me a simple open source Android native game with a set gameplay time ( aka some racing game where the duration could be 3-5 min depending on the players actions, but not infinite) and possibly different levels of difficulty.

Yes I googled this and I found several good ones, but I am looking for more suggestions.