Neat game. Really like the art. Core gameplay is solid but lacks a bit of depth. Everything just moves left and doesn't attack or move differently.
Some other things I noticed.
- It looks like coins aren't being used for anything,
- There is no limit on your vertical position so you can infinitely fall away from the screen.
- I found it very hard to die (maybe because I like hard games though)
Other than that. I think it's pretty solid for what it's doing, but I'd suggest trying to give more challenge to the player and make the player have more choices to make.
I'll be following this, because I really like procedural games like this. Hope to see some more improvements!