Very good horizontal shmup, although I think it's the worst CAVE game. Don't get me wrong, it's still great, but could have been better.

If you can look past the ecchi-centric gothic lolita art style of this series, there is a really solid horizontal bullet hell shooter here. If you're a fan of Gradius and the like then this should be right up your alley.

Cave shooters are my favorite and the Deathsmiles games are the absolute best horizontal shmups I've ever played.