Not bad at all. Very retro, too advert heavy – Space intruders: Galactic Attack Review

If you can click past the advertising wasteland of the game to successfully reach the game to play it... You will find a very enjoyable space pattern shooter (think Galaga where you have to dodge the alien foe fly in patterns). There are no upgrades or goals aside from "higher score" and survive (also very retro). The enemies resemble non-infringement "Space Invaders" knockoffs, the weapons are enjoyable (but not upgradable). Upside is that all the obnoxious advertising isn't to win in-game token credits, but it doesn't overwhelm the game when playing (advert screen pops up at the end of a level though). As a bonus, you can mute the music at the "pause" screen and the music is a semi-tolerable loop which doesn't really annoy until about 3 to 5 minutes of gameplay (which a long time in regards to my tolerance for game music repeat loops).
Review by Matrix29bear on Space intruders: Galactic Attack.