Yes! Generating ideas is always difficult, so I sometimes clone many popular games and simply change their mechanics. In my opinion, this immediately gives me an idea of what the final game should look like.
Regarding levels: I think it's not the quantity that's important, but the quality and variety. Heck, guys and I still play Quake 3 on the 3-5 maps that we liked the most, and we've been doing so for a long time!
I'll definitely see what you've done there)