Thanks for the review and suggestions! I was originally only going to have one level and make it last forever but did end up creating a few different ones but the score to achieve to actually get to them isn't balanced very well... (and the last level just gives you "survive" as a goal like Halo Reach). And yep the way different elements are introduced is quite poor too, you start with 4 guns and there's no introduction to what they actually do differently...