That idea is a bit...outdated. I visited a buddhist monastery for a few times. I feel that there's already enough colourful artifacts to look at. A computer game don't seem to mix with buddhism if you ask me.
What people look for in a game these days, is a game that's simple, yet fun. Hey you know the religion buddism isn't about fighting?. I just don't exactly know how you make the gameplay fun. What I'm trying to say is, don't expect a lot of gamers to play your game. If the idea of the game itself is not about fighting.
Also, how exactly are you going let the "hero" do the bad actions in game, if the game it's about buddhism. Unless it's not really about buddhism, and just a game about people killing people, and reincarnation.