Cogs is a steampunk puzzle game based on a classic mechanic. You have a tiled board with one free space, and you slide tiles around to arrive at the solution. Hopefully you know what I mean, and if not, it should become obvious by the screenshots. Puzzles increase in complexity, incorporating steam pipes, gears, transmission, and levers.
Cogs won several indie game awards for its art direction and puzzle gameplay. Curiously, the PC version scored ten points lower than the iOS version's 83%. I can't seem to figure out why the scores are different. Anyway, critics enjoyed the steampunk aesthetic and the wide variety of levels, but were less pleased with the extreme difficulty of some of the later puzzles.
Cogs received a couple of Portal-themed levels for the Portal 2 Potato Sack event, as well as a couple of minor bug fixes.
I love the steampunk theme. It goes beyond just the visuals -- the puzzle mechanics themselves revolve around steam, gears, and copper pipes on wood panelling. The UI also follows the theme, with lots of brass and mechanical components in the animated menus.
The early puzzles are relatively simple, but the game has a steep learning curve. For example, there are levels that require you to pay attention to both sides of the panel, because each tile has something different on each side. So with each move, you might connect some gears together on one side, but disconnect a pipe on the other. There are some misleading puzzles that seem to offer multiple paths to the goal, but after some tinkering, you discover that only one path actually works, due to the array of tiles available.
A nice touch is the challenge mode. In normal gameplay, you do your best to solve the puzzle, gaining bonus points the less time and the fewer moves it takes you. There are two challenge types: time restricted and move restricted, where you try to beat the exact same puzzles without going over the allowed limit. It's an extra challenge that adds a new layer to existing puzzles.
Cogs is both strengthened and restricted by its chosen gameplay style. On the one hand, it's dead simple to learn -- you move tiles by sliding into empty spaces, and try to arrange them to solve the puzzle. On the other hand, the puzzles get extremely complex, and when the game is counting your moves and time taken, you'll often get frustrated or panicked and find yourself shuffling tiles randomly in the hope of stumbling upon the solution. But on the other other hand (wait, three hands? Oh well, let's go with it), the game's ultimate depth and complexity are limited by the dead-simple core mechanic of the sliding block puzzle. There's only so much you can do.
In the end it's a pretty simple decision as to whether or not you should buy Cogs (for $10): do you like sliding tile puzzles? If no, don't get it. If yes, get it. While it has a very pretty presentation, interesting mechanics, rich and complex puzzles, and some neat objects to tinker with, it is 100% a sliding tile puzzle game. Whether or not you like those is really what makes or breaks the game, regardless of how nice it looks or how clever the puzzles are. Try the free demo on Steam -- it should be all you need to decide if you want the game.