Nice one!
While the idea of a single bullet that you must retrieve isn't particularly novel, the addition of the teleport mechanic sets it apart, adding depth to the whole thing. The game feels juicy and satisfying to play.
There were a few times the bullet passed right through the enemies without hurting them, but I guess you can't make a good game that works perfectly in only 2 days. Being near the edges is also troublesome because the enemies can spawn off screen close to you and instantly kill you.
Actually, I feel like the game would benefit from having a bigger arena, giving the player more wiggle room to operate.
Anyway, great game!