It's just a character drawn in pixels, moving 3D crates on a 2D plane. But still, The 3-D Adventures of Crate Boy
is a pretty good puzzler which doesn't take long to solve. Stack blocks to reach the exit, usually located on a higher ground.
Press the space key to pick up or drop a crate, and use the left shift key for a quick restart. You've reach the end once a secret code is revealed.
Name: The 3-D Adventures of Crate Boy