Hi, some feedback :)
1. On Firefox, this page shows a black box instead of the iframe.
To workaround the error, I looked at the page components, found the iframe source, and loaded it into a separate tab:
2. I couldn't hear any sound.
3. Choosing ESC for shop isn't a good idea for a HTML5 game, ESC normally allows the user to get out of fullscreen.
4. Whats the difference between METAL and MINE?
5. Shooting crabs is kinda fun!
6. Eventually the game ran out of crabs, is that intentional?
7. The crabs look tasty, can I eat them ...
Good luck in the game dev!