Unity is pretty good. I was *this close* (holds fingers very close together) to buying it when they made it freely available

It works perfectly under Windows.
The paid for version does have some lovely extra features, but for my personal use, they were overpriced. Things like proper realtime shadows are only in the paid for version, and the blobby shadows of the Indie version are rubbish. There are workarounds (essentially creating a sprite out of your 3D object and using that as the shadow), but I couldn't be bothered and dropped it.
With regard to the feature list below, Unity is 3D only, but you can set the camera so that it renders without perspective, effectively giving you a 2D environment.
As to the OP, it's all very well saying you have a good idea, but loads of people have those. To get others onboard, you need to have something to entice them. Even if it's only a cobbled together demo that runs on the PC. If others can see the potential in what you're trying to do, they're much more likely to want to get involved. Yes, programming it may be a hassle for you, but you'll stand a much better chance of achieving your goal.
Alternatively, get your name out there a bit. Look for projects that have a working demo but are looking for 3D artists to join their team. Submit your stuff and get your name known on a few forums. If you can come at from that angle, you might also find others are willing to work with you, simply because at the very least the game will look good!