(Full disclosure: the developer of this game supplied a review key)
This game has no story line. Instead you're just a space ship that needs to reach the end. And shoot through a bunch of enemies and bosses to get there.
The setup is nice. You get your pick from six different ship types, which give you I'd say about three different play styles. The game offers various power ups to level you up.
A level consists of a bunch of rooms, most with enemies, a bunch of shops of different type, a few secret rooms where you can (usually) trade your health for a powerup, and a miniboss and boss.
The art is nice but doesn't really pop for me, the music is good, but even though there seems to be a lot of content it does feel a bit repetitive quickly.
Verdict: A nice casual game with bullet hell but not too much hell if you don't want it. Many items and powerups and easy gameplay. It does get a little repetitive aftert some time, but which game doesn't.