At heart a 2D shooter with a 90 degree rotation gimmick and some puzzle elements. But with twists on level design that makes the gimmicks in Treasure's shmups look pedestrian. Try to go in without any spoilers if you can. A simple but clean presentation carries it through well.
Kind of a god tier game at what it seems to set out to do. Has a clear score attack focus for replayability as well.

There are a bunch of modes and settings for all player levels. e.g. Hard mode has challenging bullet patterns for fans of the genre. I'm not sure if I want to know how co-op mode works..

Some small gripes from my initial playtime: I wish I could map two shot buttons (one for tap/rapid, one for held/slow) when using Original/Traditional controls. I prefer having these on split keys and often resort to external tools if a game doesn't have it.

The player ship feels a tiny bit slow especially during focus shot. But almost everything does seem well designed around the current speed.

I didn't find the secret item collection 'minigame' fun to do. But it's not necessary for playing through the game. At best it's a reaction check (where you probably take damage intentionally) and at worst a memorization challenge for where each one appears.