Games mostly have the same business model canvas. Just decide on your
Value proposition - Better graphics? Gore? Jiggle physics? Advanced gameplay? Longer hours? More engaging characters?
Customer relations - Blog, FB, Twitter, indie press, forums.
Channels - Steam? Direct download? Publishers?
Customer segments - Male? Adult? Children? Old ladies?
Revenue streams - Sales? Merchandise?
Key resources - Artists? Unity programmers? Decide which ones are more important based on your value proposition and customer segments.
Key activities - Marketing, graphics, code, design.
Costs - Office, monitors, salaries.
Key partners -
Honestly, it doesn't actually help much as you can't really "pivot".
If you decide that "my Tomb Raider clone with better jiggle physics isn't selling", it's not like you should rip out the code. But it does tell you what to focus your marketing efforts at, and which customers. And the BMC lets you look at things as a whole... like if you're relying on hot animated girls and don't have a good animation team, there's something wrong there.
I'd suggest not spending more than a day on this though. There's a lot of other important things to do.