Good work, got the leaderboard to work by changing the url and removing "expiresAt" and stole the highscore.
It's a fun game, in the beginning it was confusing what was happening and what everything did but after realising I could just ignore the sharks and run around it was fun to pick up upgrades. In the end I think I died to something invisible, no clue what killed me. It was fun though.
Nice with homemade art and enemies, would have been fun with some enemies that were a bit harder though!
Good work.