Yeah, you need to unlock the new turrets. I uploaded the source code in the game page, you can check it out. You'll probably find some bad coding, but this is over 1 year old and I learnt a lot since then. What do you mean the turret mechanics are more fleshed out than the dodging/shooting? I think you mean that the game has too much emphasis on the turrets but there arent any shooting powerups. That's true but it was intended. If you could powerup yourself, making a nice turret combination wouldnt feel as powerful.