Short but powerful, a great adventure game...
As you start to play Beyond Good & Evil, you will instantly be reminded of The Legend of Zelda. Indeed, the gameplay is very similar to Ocarina of Time or any of the other main titles that came after, but as you play you will find that BG&E offers a little more than your typical Zelda game.
You, Jade, are a reporter on the planet Hillys during a war with the alien DomZ. I wont sit here and ruin the whole story for you, but the game world, while small, is very vibrant and colorful. You'll notice that many citizens of of Hillys are animals, and that with the graphical style will instantly remind you of a childrens book. Even so, as you play, you'll notice that the story elements are a little more mature than you typical childrens book (or Zelda game), and in a very short time, you'll be drawn into the conflict. The characters are all very well designed and written, and you'll care about them when they run into problems. The voice acting helps quite a bit in this regard. For such a cheap game, they really went the extra mile, getting good voice actors.
Gameplay, as I said, is very much like Zelda, right down to the hearts. There are a few more elements to it. You'll have companions that follow you around, and you can give them some of your hearts so they survive longer in battle. You'll find, though, that there really isn't much point, as you'll be doing most of the fighting and taking most of the damage. The companion AI in combat isn't that great. They're main gameplay purpose is to provide you with interesting puzzles, as they often require the help of your companion. In battle, companions often sit around waiting for you to tell them to use their special ability.
On my machine the game wasn't particularly buggy all around, but scattered around are a small number of really big bugs that can break your game. You'll want to manage your saves well, though it is such a problem that the games forums have clean saves that you can download if you do run into one of these big ones.
The biggest gameplay flaw is the camera. Particularly when you are in your hover boat, the camera will often spin out of control for no reason. Other times, on foot, the camera perspective will change unexpectedly and you have to switch keys to move in the same direction. These issues are usually minor, but they can get annoying sometimes.
Despite a few flaws, the action and puzzles are fun, and the story is top notch. For 10 bucks off steam, I'd definitely recommend you buy it. I'd recommend it even if it was 20, maybe even 30.