Polarity is the whole game
Ikaruga is a vertical shoot 'em up where every ship, enemy and bullet is either black or white. Your own polarity can be switched at will, and bullets matching your current color are absorbed instead of hurting you. Absorbed shots fill your energy, which you can spend on a powerful homing laser release. The catch is that you have to read the screen constantly and flip at the right moment, so getting hit is sometimes the plan rather than a failure.
Scoring works like a puzzle
The chain bonus rewards you for defeating three enemies in a row of the same polarity. That turns each wave into a small ordering problem: which targets to take first, which to hold off on, and when to flip. Building a high score feels closer to solving a pattern than to spraying bullets. The game runs through 5 levels with tactical level design and boss battles, and offers 3 difficulty levels — EASY, NORMAL and HARD — so you can change your approach depending on which one you pick. Two game modes are available: ARCADE and PROTOTYPE.
Playing together
Ikaruga supports 2 player local co-op, and there is also Double Play Mode, which lets two people play with one controller. Remote Play Together is supported, so friends can join over a connection as well. The game also works with Xbox360 controller, Keyboard and Mouse.
Before you start
Expect a difficult, fast game — the tag list includes Difficult and Bullet Hell for a reason. Vertical screen mode is supported, and you can rotate the game screen to play it like a side-scrolling shooter instead. Replay data can be saved, and replays can be downloaded from the Leaderboards. Spectacular 3D graphics, fast and smooth gameplay, and a great soundtrack round out the package.