Graphics are great, gameplay was smooth for the most case. Ships were nicely detailed.
Voice acting needs alot of work. The main character has a really odd voice, specially when she 'crashes her ship' , she sounds so monotone and boring. Alot of the time depending on the character speaking, the volume fluctuated enough to not be able to really hear it to a bit too loud. With a game like this you do need voice acting since the gameplay is so fast -- No one wants to read text, but it needs to be done a good deals clearer with people who know how to voice act a bit better. I believe there was only one or two decent voices in there.
The story was rather odd and it didn't make much sense. Alot of things bothered me, such as them 'jumping' to earth, and then you going to protect the city. You end up LEVELING the whole city with your guns which makes it seem like she's more the villain by simply destroying all the buildings. This is where being able to toggle your gun on and off would of been good, you could of even had a fail/pass status.. For example you would fail if you destroyed 10 buildings or more. But obviously some mechanics would have to change. But overall, did not make much sense -- 'protection of the civilians', not really. The last boss battle the AI claims 'You should leave' to the player. Like the AI is concerned, but makes no sense because it's a 'universal' bomb, thus she'd be killed where ever she'd go. Dialog needs improvement and to be actually thought out so you don't run into odd things like that. The storyline seemed rushed to me, and you never got really tied into/understood who everyone was by the ending.
It was really crummy that some offscreen thing happened to destroy the large ship you were battling in the second boss battle. I would of LOVED to see that thing go up in smoke, instead it feels more like it was removed purely so you didn't have to make a boss level for that one.
The first boss -- the space invaders thing, I don't think should even be a boss. It was a bit oddly added. If you were to do this, you should at least make it smooth. Instead of the ships actually side panning, they jittered, which made no sense to even be in the game. Also, the whole noise bit when they moved, specially when they got faster, was loud and annoying. I wouldn't of been so bothered by this if it had smooth scrolling ships and maybe a quieter transition noise in this battle. Though I think it should of been avoided.
The last boss was the only actual 'boss' battle that interested me. The rest of them were rather boring. It was a smart idea, and actually involved other things. Panning the ship to shoot the crystal type things, and avoiding the beams which seemed to be constructed rather good, giving you enough time to dodge them if you are careful about looking at where they are about to spawn. It was a good boss battle.
Gameplay needs to be more interactive. There wasn't mcuh gameplay, most levels you can sit and let the gun do the work. Even on the last level with a couple of deaths you can get past half way by doing nothing.
The last gripe, once you win, it goes right to the title screen. Sure, you get some voice acting, but no 'congrats/you win', no storyline ending really, I don't even know how we actually stopped the bomb since it was activated and I presumed we were just attacking the outside of the ship. Maybe I missed that. But you really need a proper ending to any game so get satisfied. Look at most of the ME3 players, most of them complain about the ending, they are unsatisfied simply because of the last 15 minutes of the game. This doesn't change the fact that ME3 was a good game until that point, but ending a game like that really crushes the feelings on how players viewed the whole game. So that's the point about having a decent/rewarding game. You should have some sort of reward system if anything, like a score system, just to add something to the game, maybe have people compete a bit for the highest score.
Good luck mate.