DIM is a platformer that makes use of a (somewhat) innovative concept: the ability to switch between dimensions. The exit to the next level is almost always blocked by some obstacles that are unsolvable in one dimension, but may not even exist in another.
Being a product of the creators of the Jumper series, it is difficult not to compare the two. If Jumper is like an out-of-control roller-coaster ride, DIM is like sewing a sweater the size of a penny with needles the size of chopsticks. Jumper requires reflex, where DIM requires meticulous care.
While the dimension-switching concept may be very interesting for a while, the player would eventually realize that it's not a lot unlike solving a series of mini-levels. Nevertheless, the levels are still well-designed, and would appeal to fans of the Jumper series. The greatest weakness here may be the slow pacing. Where Jumper is repetitively intense, DIM is oftentimes repetitively patience-testing. However, just as there are vertical-shooter fans who prefer Touhou to Raiden, there may be those who prefer DIM to Jumper.
While not as intense as Jumper, DIM does a fair job of matching its predecessor series in difficulty. Unfortunately, half of the difficulty comes from over-sensitive controls in narrow passages. Once again, DIM requires more carefulness than reflex.
One major disappointment is the linear nature of solving levels. The dimension-switching capability could have been used to enable multiple ways to solve a level, allowing the player to create his/her own play style throughout the game and developing perhaps an affinity to a certain dimension due to the preferred problem solving method used there. All these possibilities, however, were not explored in the game. Of course, there is the same medal/unlockable system in DIM as the one in Jumper, which does count for something, but it is not at all what it could have been.
DIM's graphics do reinforce the mysteriousness of extra-dimensions, and is a bit more of an eye candy than Jumper. I stress, however, the phrase "a bit". While the statics during dimension-shifting and the color change may be cool at first, players will eventually notice that, like so many other parts of the game, they are not what they could have been.
Again, not much different from the Jumper series: a simplistic background tune with some sound effects for jumping and whatnot.
1. An early level in one dimension, where the player may freefall into the water
2. The same level in another (the "normal") dimension, where solid stones block the player's way
3. Intro. Yes, DIM has a story. No, it is not at all different from Jumper.