Really!!! so far I can't think of any game for the topic
So how i think of ideas is i think of 1 topic and build from that as in i think of ... "Frogs" okay what can a frog do... how about... eat the screen... in holes, and the goal is to clear the whole level in ___ seconds
so you could try that idea aswell... just think of a topic, and then think about it for like 5 minutes, if u get nothing... just think of another topic