The laser upgrade is great and I like how the shield forces you to stop moving. If you need to take a breath you certainty can at the cost of being an easier target. I did feel a little constrained. I kept getting caught on a few area of the later levels. Also I didn't realize that the laser beams from some of the enemies would bounce around. It seemed like the level of difficulty cranked up very fast. I like the enemy type, just need some time to get used to everything. This is just stuff that needs to be tweaked tho. Good game for 3 days!