Haven't played it yet but from the gameplay footage, this is by far the best doujin shmup I have ever seen.
As an avid fan of Shoot Em' Ups, this game looks like a personal heaven made just for me. The amount of playable ships and all the stages, music, bosses, all from many other shmups, (and, BONZIbuddy, for some reason, expand dong.) and all of them are amazingly ported (and buffed/nerfed) from the original.
This game is fantastic, can't wait to see more of this. Keep on shooting, STG's forever.
(PS. I'm making a series where I review Shoot Em' Ups, I want to review this game on the first episode, I'm linking it here once I upload it.)