Started to think more about it... anyone looked into Unity engine?
http://unity3d.com/
Looks pretty great, full AAA graphics and capabilities. In fact on the games list I recognise of those developers names - Ninja Theory (DMC, Heavenly Sword), Obsidian Entertainment (New Vegas). It does cost ($1500 all up or $75 a month but there's also a free version), but it looks like you can just about create your own game without any actual hard coding, what with all the assets (1000s) available. There's even full gaming kits for FPS or RPG's so the game structure is already built.
3D models for instance, there's 5000 you can purchase, mostly well under $100. You could purchase an entire games worth of creatures and characters for easily under a $1000. Which is what I'd do. ie check this out, fully animated, only $10
https://www.assetstore.unity3d.com/#/content/13626
Then I'd just need to hire a freelance coder or team up to do all the AI, but all the levels I'd build myself.
Unfortunately I can't be fucked learning a 3D modelling program to build all the levels, gave 3dsmax a go and hated it, though maya looks way better. But just don't have the time but if I were 18 instead of 33, I'd do it, it would be such an awesome opportunity to build your own game (though if I was young 18 I couldn't afford any of the tools anyway).