Nice game! I wish there was some hint on how to use the cheatcodes - I only discovered that by accident while trying to be cheeky and poking the web game with browser tricks (because I thought the cheatcodes bugged out and didn't work).
The sound design was okay. Wish there was some background music, the game was very quiet. The art was fairly good (I dig the minimalist aesthetic), though the colors felt a bit harsh. Character walk animation felt too slow with relation to how fast they were moving.
Not sure how I felt about the underground tunnels, they were sometimes long and winding with nothing exciting going on (character speed hack could've helped?), but it was surprising how much hidden stuff there was on the surface.
Good work!