I think it's a really creative mechanic for a game. It's very disorienting at first, you instinctively try to press A,S,D to move but after a while you memorize the controls and it gets easy. I think the health packs made it a little too easy. Once, I'd figured out the controls I was able to play it till I got a 15k or so score and then I quit. This definitely has a lot of potential for you to add more elements. Overall, I really enjoyed the game and thought it was very creative. Good work on the visuals as well!