From their Steam store page:
"...
Beautiful art and spaceships.
Awesome boss fights.
Addictive, ruthless.
Endless arcade gameplay.
Quick and intense sessions.
INFINITE REPLAYABILITY: levels are (practically) randomly-generated.
..."

I second that. Its all very true.

Plus, it has punch, style. It´s sleek. When you defeat a boss, you get a satisfactory explosion visually, aurally and kinectically (my xbox 360 controller rumbles). Then you go to hyperspace and it is all very satisfying to see. The screen shakes, not in a NES way, but in a Bourne movies way.

The music is top, with some rock chords and makes you want to keep shooting those bastards. It is also sticky. You will find yourself humming this music after the play. That´s partially due to its repetitiveness. Good, but few themes.

The semi randomness of enemies placement, weapons, etc makes each game restart fresh, taking part of the game over frustation away. It also plants in you the seed of addiction as after each game over you will want to play just one more cause 'this time I will get the right combination of enemy waves/weapons/upgrades to beat the game'. And you will restart many, many times. This game is hard as nails. But it has depth, the randomness is the Devil´s whisper and, of course, it´s a shmup, which I love since R-Type for the Master System. Much in contrast of what I wrote for that other game.

This game is a hidden shmup gem.