Very interesting idea!
The controls seem a bit unintuitive, maybe if down arrow could crouch too, and the character could change its sprite to a crounching sprite to give feedback to the player. Another thing, as the other jammer already commented, is this break from keys input to mouse input when interacting with a container of items, maybe there could also be a way to select items from a container using arrow keys and enter to avoid this break.
The fact that the alien has the items listed in a notebook page feels strange in context (since he is an alien) but it ends up being funny.
In my opinion this is a very good first submission, the game has some aspects to get better but in all its a complete game with a cool game loop idea (some variation would make it even better).