Really nice concept and generally well executed.
I encountered a bug a couple of times where the character would not move out of the doorway after playing the stage. I tried retrying the stage and exiting to the menu and trying again but the only thing that worked was restarting the web page entirely. No idea what caused this but it happened multiple times. Another bug that i run into once was the arrows wouldn't appear on the ground when pressed and once again i had to restart the game.
A few general gripes: It would be nice to have an undo key for if you misplace an arrow but with the level restart system that would only be a minor improvement. Another thing would be that i really like the style of the tutorial however it didn't in my mind make it clear the aim of the game but after a couple of tries i figured it out anyway so again not a major issue.
Overall really well made game with fun mechanics. Sound design is good and the graphics serve their purpose well. Although not the most fun iv'e had in a puzzle game definitely is a solid submission :D