Cute little adventure!
The level design is really nice. You did a really good job on showing a thing (Hit thing, open door) and then expanding on it (want to hit thing. Sword too short. Need another thing.)
The invincible crabs were also neat when you had to kill all the enemies to proceed.
Good work on teaching the player how to play using the environment instead of a wall of text. The inventory system is also pretty impressive. Were there more than the two items or did I miss one?