Good game! I had fun playing it, i especially liked the puzzle side of this game : ).
Altho at some point i wanted to test out if you can brute force the codes xd.
It turns out that there are 4^4=256 combinations, and with each one taking about 0.5 a second it would take aprox. 2 minutes for each door.
Also, i found a bug where i can type more then 4 arrows when spamming.
Anyways, great game, good job!