If you enjoy Touhou Project, you'll definitely enjoy this.

Bullet-Hell action fun. And anime girls. Lots of anime girls...

GundeadliGne at first seems to be a rather competent shooter in the first 2 minutes of gameplay, however the experience gradually dminishes quickly as soon as you start getting into it.

GundeadliGne is at heart a side-scrolling bullet hell (Or danmaku) shooter where you tackle enemies and bosses in order to get a high score. Just like the original, your character is able to throw an item at enemies to slow down time (which is mandatory in many sections), also new to this game are the rechargeable bombs which can be re-used after a certain amount of time and the ability to turn around to shoot enemies behind you. Probably the best addition to this game is the 2-player Co-Op that is both offline and online (never got the online to work though)
Another thing to point out is that the game will either decrease or increase its own difficulty depending on your performance during a session, similar to other games in the genre.

Where the game absolutely fails at is absolutely everything. The game again, adjusts its difficulty depending on your performance, but the way it handles it is a joke. Basically, in order to increase it, you have to either kill a boss or mini-boss, clear waves quickly, or probably the worst of them all; OVERHEAT your weapons. Considering that the alarm that rings when you're about to overheat has a delay and the heat bar is TINY, makes this design decision absolutely atrocious. And the only way to decrease the difficulty is either by getting hit or by using up a bomb, which takes time to recharge. So it is easier to increase the difficulty rather than decreasing it, making the game too hard too fast. I was able to get to the hardest difficulty before the first boss on my first playthrough, which was just evil.

Also, the patterns in this game are pretty horrid, none feel creative or fun to dodge, in fact alot of the patterns are designed to simply kill you cheaply without any good way of relying on reflexes to dodge most stuff, and considering that you have to slowdown the time by hitting enemies with a temporary spell in order to even see what's going on, that makes the experience so much worse than it already is. On top of all this, the hit detection is even more aggravating than the original since it is hard to focus on your character's weakspot (Scarf, bell, whatever depending on the character) when the patterns fly so fast and are basically the same colour.

While Gundemonium Recollection was a really well balanced shooter with some minor flaws (Except the true last boss, he is a pain to spawn and defeat), GundeadliGne has some neat ideas but absolutely fails at implementing every single one of them. For avid fans of the genre who love a good challenge with great patterns and excellent design, this is not for you. I can only recommend this to people who are fans of bullet-hell (danmaku) shooters no matter how well designed it truly is.

the second game in the series, and it improves a lot of the game. like you can fire backwards and adding a close range/melee fighter. the story is simple if you played the first one. the music is awesome like the first one. since this is a bullethell game, its gonna be hard, even on easy. the only con is hardly anyone online to duel play, which is sad. its a fun game. if you enjoy bullet hell games, i suggest picking this up

I am a long-time fan of shmups, with renewed vigor after having more recently discovered Touhou. That being said, this is without a doubt the worst example of the genre I have ever had the displeasure of having witnessed. The prominently-posed naked catgirl boss was enough for me. But even if you're into that in your games, rest assured that there is plenty wrong with this game from a gameplay perspective. Your character takes up too much of the screen, so that shots must come at you either in slow-motion or with very tight limits to the patterns that enemies can make. You have a small but unclear hitbox, which is unfortunately imperative to use with some of the spread gaps in attacks. Some hostile radial bursts even have no apparent gap, as though the developer didn't realize he'd made a no-health-bar shmup. It's rather important to use the special abilities at your disposal, which the game made no attempt to explain how to use or how they work.
The ONLY good thing I can say about this game is the ability to co-op. Combined with the ability to aim backwards along with enemies that make use of that mechanic, could lead to good teamwork moments if the game was any good. As is, inviting another person to play is a passive-aggressive way to let them know you hate them enough to suffer along with them so long as they suffer too, but without telling them to their face. Having Reimu as a boss is just insulting, as though this creation has any right to call itself in the same league. GundeadliGne as well as the Gundomonium collection remain the only games I wish Steam would let me fully delete from my library.