Sometimes a puzzle game comes along that's so smart and so well-made, you wonder why it wasn't created like a billion years ago or something. Puzzle Retreat from The Voxel Agents is one such game, combining elements from sokoban and a sliding block puzzle to create an impressively challenging game that is almost completely void of frustration. You just sit, stare, and play, all while marveling at the beautiful visuals before your eyes.

There are just two rules in Puzzle Retreat: fill in the gaps, and use all of the blocks. Tap an ice block and slide your finger to push it/them in any direction. Blocks slide over previously filled spaces until they land in an empty slot, and multiple blocks fall out like a series of dominos. It starts with simple blocks that distribute one, two or three cubes per slide, then progresses to include directional arrows and fire blocks that erase some of your hard work. It never gets too complicated, and one thing Puzzle Retreat does so remarkably well is keep everything simple, relaxing, and pleasingly full of challenge.

Puzzle Retreat could almost be played on an old wooden table with a few ice cubes. Except, that would be messy, and not nearly as varied. Plus: your grandmother's antique table! What were you thinking?! That homegrown simplicity is what makes it such a captivating game. The standard version includes almost 100 puzzles, and several puzzle packs are available to purchase if you run out of grids to fill. Until then, start up the logic side of your brain, and get ready to use the undo button!