Battle Block Theater is a puzzle adventure game that can be played single player as well as co-op or PVP that costs $14.99.
The core gameplay consists of 2D puzzle platforming where the player must collect gems in a level and then reach the exit. For what sounds simple enough can at times be excruciatingly difficult.
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Pros
Pro Co-op adds a completely new element to the gameplay
There is a modified co-op campaign in the game where players must coordinate their actions to succeed. This makes for a fun couch co-op game due to the communication one must have with their partner as well as how fun it is to grief them in person.
Pro Well thought out presentation 
From the witty humor, enjoyable songs or the theater cutscenes, BattleBlock shows a high level of consideration for its design.
Pro Well balanced difficulty curve
The difficulty curve for Battle Block Theater is so evenly programmed that the player will barely notice that it is progressively getting more difficult. It really does a swell job of integrating the player to where they can handle any challenge the game throws at them.
Cons
Con Co-op mode isn't easy to get started right from the get-go
Con Competitive play feels lackluster
Competitive play is not as enjoyable as the co-op modes due to stiff combat, really the mechanics of this wear out pretty quickly.