If we say the Hamsterball is based on "speed + balance", and the Ballance (3D Balance Ball) bases on "balance + gravity", then this Puzzle Dimension is a rolling & jumping ball game in twisted 3D space based on the "puzzle + maze" elements.
Layer MAZE is a series of small puzzle games with creative layer-structured maze elements, developed by PipkinGames. Its difficulty is not hard - even a bit low for some players with good memory. However, it can exercise a person's brain energy enough - reaction speed and short-term memory.
Road Blocks is another maze-based series of small game. At first sight, Road Blocks is exactly the same with Orbox series. But apparently Road Blocks is much like the ancestor of similar games!
Open Doors is a Sokoban style (both interface and operation) series of small puzzle games, yet it's a quite another gaming style and concept. Endless changes are derived from its simple design, on the whole it tests the players' logical thinking ability - the chain reaction caused by the every move needs to be considered clearly.
Orbox is a very nice series of maze style puzzle games released by ArcadeCabin, simple but addictive, and each level requires your brain to run.
N is a classic and challenging 2D flash based game with simple graphics, very resistant to play. The action design of Ninja is pretty darned realistic and cool, which gives extremely high request to the player's reaction speed and balance ability.
SHIFT is a series of puzzle flash games with exquisite design (using the concept of reversing black and white worlds). They just seem very simple, but for most of stages to clear, you have to shake your brain and need to cooperate with reasonable key controls to get through all the maze.