Do not under any circumstances work by yourself, this caused my epic fail a year or two ago, I lost interest simply because others did. Here's my (CRAPPY) Engine test, just don't fail it like I did.
http://oddworld-toff.site-forums.com...wnload-t82.htm
Another tip I'll give you is Don't attack this all at once, create a work flow.
e.g. Engine - Graphics - Sound - Script - Level Design - Code - Cutscenes - Aesthetics etc. If you're no good at script writing get a fan fiction writer to do one for the game (They'd love that). And get decent voice actors (Many people will do it for free just for the love of doing it).
Don't announce big plans either, that puts pressure on you to do it (not fun) and you'll most likely crash and burn like me.
Hope I could help you, Good Luck.
Edit: Damn the DL is broken, well I can't be bothered to turn my Old PC back on.