Zen-Ichi is a manic shooter. Think about Battle Garegga for the rank control and Dodonpachi for the colorful bullets. Here's an overview of the game system by Iaspis and shoe-sama. It's quoted from the shmup forum.
"It's a decent looking shmup, focusing mainly on gameplay.
In the beginning, you have 3 types of craft to choose from, each with its own main weapon that can be powered up a bit by collecting certain pick ups. The game starts on the easy side but evenyually gets pretty manic, which is fine by me.
The main trick of the game is to harvest as many blue crystals as you can, filling the upper crystal meter, so that you may either replenish your one-hit shield (in case you lost it), or have the chance to enter super harvest mode, where you can collect purple crystals (instead of blue) that fill up your bomb meter, thus gain more bombs. Bullet scratching also fills your bomb meter but at a very slow rate.
The weak point of the game is sprite design. The ships look blury and a bit choppy, which can't be good. The backgrounds are a bit monotonous too, The weak point of the game is sprite design. The ships look blury and a bit choppy, which can't be good. The backgrounds are a bit monotonous too, but hey, that was the case in ChoRenSha (which still rocks) wasn't it? Still, the gameplay makes up for these drawbacks in my oppinion. What do you think of it?"
"1) quickshots to increase rate for end of stage bonus, bomb and fever distribution for items, special requirements for spawning certain enemies
2) lol uh you need to take hits (during fever lowers rank most iirc) for rank control to make stage 4 and 5 scoring (and survival, having max lives is also good for scoring lol) a lot more manageable of course expert mode gets rid of rank control entirely, since hits = death"
It's available for free during a limited time as a 10 year anniversary gift. If you got a 503 error wait a bit and retry.