I'm curious as to your reasoning behind spending 2 years developing this in HTML5? The art style is great and all, but you could have knocked up a game like this in an engine like Unity within 3 months and deployed it to iOS, PC/MAC, even Xbox Arcade.
I think that's an optimistic prediction for a game of professional quality, done by a single person. I reckon most of the work is edge cases, art & sound, tweaking, bug fixing, not working on the generic engine.
You could save time by doing this though, as you say. I'm leaning more towards the idea of reusing code and trusting other peoples engines at this point. But we've all made our own engines and, as other posters have said, this is the guys hobby, and most likely a labour of love.