Blocky is an arcade game based on block-breaking games, though in a 3D world. The game is much more dynamic than these typical ones however, firstly the 'blocks' that need to be broken come in many different shapes, and will often move and attack the player by firing balls similar to that of the player.
These 'enemy blocks' also have a health value, which is shown by portions of the block breaking off. This allows some blocks to have a regenerative effect which activates after a period of time, creating a need for the player to hit the same brick in quick succession.
The 3D world would create great difficulty in aiming for the player, so the ball may be controlled through a magnet style effect. The player in fact has access to another ball of a different type. This ball attracts the other ball, and is attracted to the player, thus it may be fired to 'curve' the first ball.
Different levels in the game introduce different enemies, and upgrades for the player.
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Spacer is a puzzle game played in the first person, alike to the Portal series. The player is given not a portal gun however, but a 'space capturer'. The 'space capturer' takes a 3D space in front of the player, captures it into a 2D surface, and a wall is created in its place. This surface can be then placed on a wall, at which point the captured space is moved to the position of the wall.
The objective of the game is to reach the exit, which is initially inaccessible. The player must capture specific areas that may for instance include a staircase or an elevator. When placing these in the correct location, the exit can be reached.
An interesting use of this 'space capturer' is when it captures a space horizontally, but is placed such that the space becomes vertical. This could be used if the exit is below or above the player. At all times, the exit is highlighted through walls so that the player knows where to head.
Image source M. C. Escher, retrieved 1/08/2016 from https://fineartebooks.wordpress.com/2012/04/19/when-art-intersects-with-mathematics-constantin-brancusi-m-c-escher-and-cristian-todie/