I dig this game - it took a while to understand the controls but once I did it was a pretty cool puzzle game! I'm convinced one of the doors is impossible to beat, and I ran into a second door where I think the texture that shows the pattern to open it was missing.
I agree with other commenters that at least a little instruction on which keys must be used for the "u l r d" inputs would be helpful, I was trying to use the arrow keys before realizing that wasn't the solution.