Art and sound fit together nicely, good job! Those things which catch you and make the screen red are annoying, because you have to die to get rid of the redness... And if you respawn, the enemies should respawn to strategic points too, otherwise you will end up very close to them and covering your way back from a dead end.
Are those "crosses" and small "arrowheads" (white sprites) throughout the tunnels suppose to mean something? I've been trying to figure out their logic...