Horizontal, bullet hell type of shmup
This is a unique shmup, but not made for everyone. That because of the anime style, some seminudity (removable and NOT needed to enjoy the game, explained later on), fast pace (subjective), and taking a while to getting used to the controls, binding all the many keys to your liking, learning how to use the game features (getting rid of bullets with planeshift, controlling Phase Level), and so on. Once you learn how to play the game properly, it can be really fun, and the online duet revolutionates.
Gameplay: Good (3/4)
The gameplay is fluid, resposive and satisfying. An issue I do not share, but many people seem to do, is that there are many keys for many functions. Your regular shmup has a fire and bomb key, and sometimes a focus or slow-down and a charge attack key. GundeadliGne has fire, rapid fire, mana shot, bomb, focus or slow down, turn, and even a screenshot key! The best way to play the game seems to be in a controller or an arcade stick. Personally, I have to admit that it took me a while to use all keys properly.
The two initial characters are said to be one for average players, that is Eryth, and one for beginners, Elixirel. Eryth can only shoot straight, is faster than Elixirel and seems to be able to cause much more damage (don't rapid fire too much or her guns will heat up too much). Elixirel is able to fire to to various places so you shouldn't bother staying in the front of a boss to do damage, but she's slower than Eryth and sometimes it costs you a life. The bosses bring innovative bullet patterns, most of the time, but either they are good or not is subjective. I say they are.
If you're too slow to destroy enemy waves, you'll run out of time and may not be able to finish a mini boss or a boss itself. So the game requires you to go fast, but there's an issue few people might experience. Depending on your computer's hardware, the game may run slower in fullscreen mode and a tad faster in windowed mode. That happened to me, and for some motive I can't get my game to run on fullscreen mode anymore, so I was quite shocked at the difference.
If you're scoring high in the game or pulling out death bombs, you'll raise your Phase Level, making the game harder. If you're not ready for high Phase Levels, try using bombs before being hit or even don't bomb at all. Giving up a feel lives to not lose them all is the key. It's not explained in the game, but there's a manual you can check by right clicking GundeadliGne in your game library, and it's recommended you do so, as many other features are also explained there.
Game Visuals and Music: Moderate (2/4)
The pixelated graphics are nicely worked, representing what they are meant to. A problem is the seminudity of some of the bosses, that can be hidden editing the .ini file in the game folder. The seminudity turns the game down for some people, making they think that this game is trying to sell with sexual content, but that's NOT the case. In my point of view, It's supposed to add to the chaotic climate of the game, just like in Bayonetta. The characters and other bosses are well designed.
The music quality is subjective. The original music is not the greatest out there, neither the arranged version, but they fit so nicely, it seems they are better than they actually are. I was surprised when listening to the game OST on YouTube, as they didn't feel so awesome as in the game.
Game Storyline: Moderate (2/4)
Not really the focus of the game (so it's discounted from the overall rating). The story is presented between stages of the game, a screen of text alongside with character art. It's not the most enticing way to tell a story, but the story itself isn't shallow, neither badly written and translated. It's a continuation of the previous game, Gundemonium Collection. If you want to read it, you can check GundeadliGne's TVTropes page.
Game Entertainment: Good (3/4)
As some people would have trouble adapting to the game's many features, and some people would think bad of this game because of the seminudity, I can't say those people would feel entertained playing GundeadliGne. But if you fit the target demographic of the game, several hours of fun are guaranteed. And even better, if you happen to have a friend that owns the game and lives in the same country as you, both of you can experience the online duet at it's best, that is absolutely fantastic. However, if you're playing with someone from other country, you'll have connection issues and the controls are going to be far from responsive.
Excellent game for people that are okay with all the items listed in the introduction of this review, and have someone to play the online duet mode properly.
Good game for the standard shmup player, but they might have a bad time adapting to the controls and game features, also if they don't mind the anime style and seminudity.
Moderate game for beginners, people that would give up on trying to understand the controls and game features, and only playing the game to pass some little time, also being or not being slightly triggered by the seminudity.
Bad game for people that dislike the anime style overall, that would like to pilot a ship rather, also that thinks that the controls and game features are unnecessarily complicated and that also thinks that the seminudity is there to "help selling a bad game".