Thanks for playing! I get what you mean about the movement speed. I did that to create the feeling of moving underwater, but I do have to agree that it might make things a bit too sluggish, even if the boost ability you get later on does improve things a bit, though altering it would mean reworking the entire map and some of the mechanics to balance things out.
As for adding WASD and space support, I am currently working on a patch to fix a few bugs I found just now, so I will do that as well!
EDIT: Just uploaded the patch, so there is WASD and Space support now!