The name "GraidKaruPachi" is totally appropriate here...the gameplay is an odd hybrid of Dodonpachi's chain system and Gradius' low bullet count, high challenge pattern. The true last boss appears to be inspired by Ikaruga's /Radiant Silvergun's Stone-Like , so there's the Ikaruga element of the game.
Looking beyond the tasteful premise , we have a decent shmup that is marred by some serious issues. First and foremost, the chaining system is poorly implemented. Like Dodonpachi Saidaioujou and the later versions of Dodonpachi Daifukkatsu, dying, or getting damaged do not break your combo, though they invariably hurt your scoring. For a game of Daifukkatsu's difficulty, I find this to be a welcome addition...but to a game like this, it kind of devalues chaining, especially considering the fact that chaining is even preserved on bombing.
To compound matters, the chaining meter itself has several issues, and some are sadly things that not a mere programming tweak could fix. First and foremost, there is no meter letting us know how long our chain will stay up. This makes chaining almost impossible to time...but no matter! The timer on the chain is so merciful that even without the powerup, there are only a few segments, primarily in stage one, where your chain will ever be in danger of being broken. Due to the wide shot of the ship, chaining feels like it's an afterthought.
But if the creator were to shorten the chaining time limit, it would become impossible to link the chain through the entire stage. This game falls into the same pitfall that haunts virtually every flash shmup (even bullet heaven, praised as it is, is not immune): the enemy spawns seem to appear in "waves," rather than actually arriving fluidly , as they might in a high budget CAVE shmup. Unfortunately, the chaining system of Dodonpachi does not sync well with this, and scoring is thus pretty broken.
The patterns themselves are very much in line with those of Gradius, with many enemies simply aiming their bullets at the player and firing rapidly. This worked in gradius because of the interaction the player had with the environments and the ability of the enemies to provide threats from all sides..but here, there really isn't much thought into evading the enemy onslaughts.
The true final boss(HUGE difficulty spike, here) itself has a really questionable design. Its movements are scripted, but jarringly fast, making the fight largely a matter of tanking through the "intense" phases and memorizing the more subdued ones. If you had given the ship a visible hitbox, the battle would have been more doable. The pattern in which it spawns its turrets is particularly glaring: the turrets can literally appear out of nowhere and spawn on top of the ship , dealing unavoidable damage. I do feel that the concept of perfectly syncing the fight to the passionate music in the background is a good idea, and I certainly breathed a sigh of relief and felt a feeling of exhilaration when I realized that I had finally cleared cruel mode... but the execution here is just not what it should be.
On the subject of music: the stage 1 theme, while appropriate for a desert stage, is not appropriate for a stage 1 theme.
The rest of the bosses aren't really very difficult, though I must admit that the stage three boss is pretty interesting.
All in all, I think that this game has some good ideas at a conceptual level, but in execution, it doesn't live up to the legacies of the games that it pays homage to. The upgrade system, while commonplace in flash shmups, feels like a departure form their design in favor of something more typical of a standard flash game. It appeals to casual players who NEED dangling carrots to keep on playing, but the game should be able to function without them. Making quality flash shmups is tough, and this game is a step in the right direction. The design here just needs to be further refined.