Yeah I have that problem but I stand in one place and the enemy comes to me and I kill the enemy and still win the level its easy... Its just a deathmatch vs. a noob...
Oh, yes, that's right, I experienced that before, it happens to everyone, that's just the background of space, it's kind of stupid because when you try to move it makes you fall and it says "??? thought he could fly" I mean like, WTF? But it's funny when other people do that..