Starting last thursday I began developing a small game ( Using C++, SDL and OpenGL 1.1). The game is very much in the style of Squares 2, as seen here: http://www.ebaumsworld.com/squares.html However, I don't want to rip a game design, so I was wondering how I could make such a game more interesting, and certainly more fun. I myself have a very limited imagination, if I was creative I wouldn't be looking around on the internet for game ideas to stea- borrow! So what do you guys think? How could this be more fun?

Hmm add a cat as the character to be controlled

oh wait that's been done:
http://www.newgrounds.com/portal/view/217024

To state the obvious, more powerups. How 'bout obtacles, or something?

Hmm add an underwater theme to the game

oh wait that's been done:
http://www.xgenstudios.com/play/fishy/



sorry, couldn't resist :P
How about little boss battles to mix up the pace? For example, some bosses could have patterns that you have to dodge without getting hit.. Maybe by left clicking you could even drop some mines to use against the boss.

I find this "oh wait it's been done" comment rather negative. I mean lets be honest, would any commercial games ever be made if developers stopped because they realised it's been done. There is very little imagination left in game development, and sure it is a bad thing, but that doesn't stop you from giving positive ideas to boost an already tried idea.