Trine is a 2D action puzzle-platformer, featuring three characters you can cycle between. There's a Knight with sword and shield, Rogue who attacks with a bow and can swing on wooden areas with grappling hook, and a Wizard who can move objects, conjure boxes, (later on can conjure) planks, but has no dedicated attack. He can conjure boxes and drop them on enemy's heads though, or later in the game, can throw them.
The game is very much focussed on physics, and you must use your character's abilities to navigate the areas. Often, you will use the Wizard to place boxes or planks as makeshift bridges or ramps. The Rogue's grappling hook can be extremely useful in certain areas. She has unlockable ice arrows which can be used to make frozen platforms on water, and fire arrows to destroy some wooden constructs. The Knight is mainly used for combat scenarios against the enemies, but can destroy rocky walls with his hammer, and can block hazardous fireballs, acid or projectiles with his shield. I thought the main game was lacking for the Rogue but she is very useful in the DLC.
The enemies usually come in the form of goblins, but there are times in the game where you are pitted against other enemies such as spiders or ogres. The combat mainly feels like busywork and just to add a deviation from the puzzles.
I thought the puzzles were quite mixed. Some puzzles I was convinced I wasn't using the correct solutions, but managing to brute force past them. Other puzzles can be really clever and make great use of the physics. Creativity can be a brilliant part of the game though, so it is good that there are often many solutions to each problem.
There are plenty of traps such as spikes, lava, swinging spiked balls, and falling rocks which can make navigating the areas more tricky.
If your characters die, you need to reach a checkpoint to revive them. The checkpoints are fairly close together, so this isn't a huge problem.
The mechanics allow for great co-op gameplay, and produce many moments of brilliance when you work together. You can still switch characters but you can't be the same character, so must communicate effectively to help each other out. The game creates plenty of scenarios that you will find humorous in multiplayer since your actions can send your friend tumbling down a pit to their death.
There's collectibles to find; usually vials that give you experience so you can level up. You can gain new abilities or gain stronger attacks. Certain abilities are mandatory at some points in the game. So if you don't have the ability, you will have to go back to the skills menu and reset your points. This was quite annoying since I spent several minutes trying to get past a certain section then had the idea of returning to the skills menu.
The game can be completed around 5 hours, with an extra couple of hours for the DLC.
Trine is a decent game but I felt it didn't feel as fresh and exciting as the original game. Some parts of the game were very clunky. There were plenty of fun parts which come organically from your creative solutions, or mistakes.