Feels like painting the White House...
..With a toothbrush. I mean, You start off really fast with waves from every direction while our puny little lazors are barely useful aganist front enemies (can't decide if that's due to the huge lag i experienced or really small hitboxes), I didn't see powerups of any kind to help keepin' enemies nuber low, so the fun fell down to just dodge them the best i could, until the boss showed up, killing me so quietly with his boomerang-effect laser I didn't even notice i was taking damage, 'till i went kaboom. I checked the menu for quality settings (and resorted to right clicking the low quality, with no evident effects), dimmed lights, looked for further instructions, but I failed in each action, so i just rage-quitted.
Now, after quite some time spent with my pc, I learned not to judge too hard the games when i can't play them due to heavy lag, I know it's not your fault (well... not entirely xD), but putting that aside i couldn't find, let's say, nothing too new or interesting in terms of gaming, just good graphics and stuff...
So, to shut me up: some lag-control settings will help uor rusty pc to run properly, any kind of evolution system (power ups, leveling up, buying, whatever does) would give some crunch to the blasting, and.... i think i'm done.
I feel somewhat sorry for a mere 6, i look forward to give you more on your next submission!