If you have a deep love for classic shooters, you should play Ikaruga.
I'll never be a great Ikaruga player, and that's fine. I've come to terms with that. But that doesn't mean I can't stand at a safe distance and appreciate it from afar. While some people would claim that most 2D overhead shooter worship comes from a very pretentious place that's usually reserved for wine snobbery, you don't need to be some high-falutin' games-as-art nerd to appreciate Ikaruga.
Though, I feel it's necessary to say up front that Ikaruga certainly isn't for everyone. You may hear people go on and on about how it's an amazing, museum-worthy masterpiece. But if your brain isn't wired to appreciate a top-down shooter, no amount of praise is going to make this game seem as special as many claim, and it's likely that most people will find it completely impenetrable. Consider that your last warning on the subject.
OK, so Ikaruga? It's an amazing, museum-worthy masterpiece. Though when you break it down and start to talk about it in a mechanical fashion, it might not seem as immediately impressive. It's a five-level top-down shooter with no power-ups. The trick is that you can flip the polarity of your ship from white to black and back again with the press of a button. This is the game's key mechanic, as you can safely absorb same-colored enemy fire, which charges up a homing laser attack. Also, every enemy is colored white or black, as are your shots, depending on your current polarity. You can do double-damage to enemy ships by attacking them with their opposing color. It helps your score and end-of-round rating if you attack same-colored ships in a row, as you can chain together these kills for combo points.
Enemies and bullets come at you at a pretty constant rate, and there's a very maze-like quality to certain portions of the game, where you'll have to analyze the pattern of incoming fire, make sure your ship is the right color, and carefully maneuver your way through safely. This gets pretty hard. At the end of each stage, you encounter a boss, and even more bullets head your way, making you think faster to survive the hail of bullets while dealing damage of your own.
It's the chain combos that separate Ikaruga from your average shooter and elevate it to some kind of weird art-form. Watching replays of expert players achieve S rankings has an elegant, poetry-in-motion feel that makes you realize that your pathetic C+ ranking is the equivalent of a caveman banging on rocks with an Xbox 360 controller.
In fact, that might be reason enough for some people to pick up the 360 version, as it has the option download and show the highest-ranking replays from the leaderboards. So at any point you can go watch someone else play and realize how pathetic you truly are. The catch is that replays can only be saved using the game's default settings, so if you finally stumble your way through the fourth level, you won't be able to show your friends until you can do it without continuing. Yes, by default, continuing is disabled. But you can turn it on for three continues, and you'll earn additional credits as your overall playtime increases, just like the Dreamcast release.
The game looks great and crisp running in HD, and if you're so equipped (or are really good at playing games while laying on your side), you can rotate the view for a vertical view, much like the arcade version.
If you're a crazed Ikaruga purist, you should know that the top player on the leaderboards has come out and complained about the accuracy of the 360 version, saying that some enemy placement has changed. And after watching his replay, well... he would know. But chances are you won't notice. The only real negative I can see comes from the online play, which can get stuttery on some connections, making an already-hard game practically unplayable.
The only serious obstacle, however, lies with you and your own personal taste for top-down shooters. Just because it's great doesn't mean it's accessible. So keep that in mind as you weigh your options for this $10 XBLA download.