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Basics: You save people(plus one dog) from various dangerous situations. After you reach them on the level they snap out of their panicked state and become playable characters. It is through astute sequential use of everyone's specific skillset that you figure out the way to get them all safely to the exit.

Examples of some of each character's precise abilities and limitations are what size blocks one can push, how far of a gap one can leap, how high of a platform or block can one climb up on or jump down from etc.

Every set of ten levels has a different theme and often introduces a unique puzzle mechanic, such as ice, movable platforms, balances, rock or cement barriers, swimmable water, directable conveyors and others.

Pros:

Levels are generally cleverly and sometimes ingeniously designed.
The levels are challenging enough that 150 is enough to last you a long time(I would estimate more than 20 hours worth of gameplay for most players).
Almost no precise timing or reflex actions needed, just careful thought and analysis of the specifics of the situation.
Plenty of levels are always unlocked for you, so if you are having trouble with one, you can always try another.

Cons:

Doesn't record the total time you spent or the number of attempts before you solved a level.
The physics of how some items behave in the game doesn't always match the real world eg for some solutions you stack blocks in ways that would topple over in reality(This isn't a real big deal, you just have to get used to and accept the game's reality).
No option to turn off phrases that the characters use repetitively.

Comments: This is one of my favorite DS games; I really enjoyed its challenge. In terms of the type of puzzle solving required, it reminded me alot of Toki Tori and Adventures of Lolo, so if you like those you definitely will enjoy Exit DS.

Also there is a sequel, Exit 2, that was released on Xbox Live Arcade which is worth getting if you liked this one(Unfortunately it doesn't look like it will be released on DS).
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