Nice game. I played it through on Easy, but Normal seems playable and not too much harder now. The key is to follow the arrow, and don't try to clear the level )
Really expected a worm in the end, do you fight it only on Normal difficulty? Or, maybe, the corridor itself was the worm?
In the keybindings, 'u' is set for inventory, but it collides with "hjklyubn", I had to reset that.
It seems that bent geometry of some map pieces is not easy to incorporate into otherwise rectangular map. Shooting can be problemmatic. Crossing bent corridors is probably difficult to implement - you have to somehow decide how to rotate the map correctly. Your approach was probably to break the map into a bunch of rectangular pieces and "magically" join them, so that units "teleport" between these pieces. Looks interesting, sadly it did not become a significant feature of the game. Still, it was fun to walk through these corridors, especially in the last fight, it added some unsteady off balance feeling, which is really awesome.