A beautiful 2D platform-puzzler that is fun alone or with friends.
The gameplay could be called shallow, but when you combine it with the characters' abilities and the builds of the levels, it is really quite ingenious. There are multiple ways to pass every barrier, be it a wall or chasm, and you often you will realize easier method after completing it.
My only complaints are about the duration, which is too short, and the story, which is too shallow. The latter is caused by the former, to be sure. However, the devs sure did pack a lot of value into a weekend game. Besides, it has good replayability when you throw in the co-op option. Do you help your friend...or drop them in the lava? It is a dilemma!
The first thing I noticed, as I imagine do most other Triners, is the eye candy. Yes, Trine is beautiful. The backgrounds are deeply colored and highly detailed. I probably died a few times because I was distracted by something amazing in the background. The characters themselves are also very well-animated.
You can play as one of three fantasy staples: a wizard, a warrior, or a thief. The wizard is not a very good one, and his abilities are limited to conjuration of inanimate objects. The fighter can fight and throw stuff. The thief can shoot arrows and grapple from anything wooden. So the wizard is the one character who cannot fight directly, although his conjurations have the ability to crush if dropped from above. All characters seem to have the same jumping ability and speed, so it seems that it is only their appearances and special abilities that distinguish them. The characters level up by collecting the green orbs that are hidden throughout the levels and sometimes earned from combat. Leveling up each enhances their core abilities: wizard can summon more stuff, the thief shoots more arrows, and the warrior gets stronger and gains a flaming sword. The characters can retrieve items from chests sprinkled (sometimes hidden) throughout the levels. These items grant health and other bonuses, some of which are extremely useful (unlimited breathing underwater).
Enemy variety is limited mostly to skeletons. They wear more armor as the game progresses, and eventually you encounter those with a shield and even those that spray fire at you. However, they are all bone. Occassionally there are some ogres and the odious bats, but the enemy variety is limited. There is a final boss, but you don't defeat him so much as defeat his level. So the combat is limited in Trine, but I would argue that combat isn't the point.
The point is the progression through a level. Some are quick to call this a puzzle game, but I think it is more a platformer with puzzle elements. For example, you have a lake of acid. In the middle of that lake is a rock island, but it is too far away to jump. If you are using the wizard, you can creat platforms and boxes upon which you may cross. If your wizard is unaccessible, then perhaps the thief can find something to which she can attach her grappling hook. Or, if you're doing 2 player, you can have the warrior throw an object that has the other player's character standing on it. I was never that confounded by a level, so it really isn't that difficult even on 1player, although I do think the last level (which is a huge jump in difficulty) would be easier on 1 player.
There may not be much meat on the bone when it comes to Trine, but it is extremely high quality. It's great to see 2D is still alive in games like Trine.