If you are targeting an audience who is willing to look at indie games, I don't think you need "3D" to be successful.
To my knowledge there is no real usable 3D-engine on the market with the ease of use anywhere near C2.
You have to consider that even with an engine like unity the time to set up your basic project mechanics without producing any real content can be as long as the complete timeframe to develop a C2 game.
I'm totally with GenkiGenga on this.