As we grow up, we lose our passion for ripping open machinery to watch gears click and whirr.

Why is that? Are we, as adults, ashamed to take hammers and screwdrivers to everything with a mechanical heart? Do we become our parents, suddenly made aware of how expensive machinery is?

Either way, Skyfish Studios's A Mechanical Story offers a cheap, clean, and fun way to muck around with gears. Brush off your thinking cap if you choose to dive in, though.

There are no hints here - not for free, not for cash. You're on your own, same as you were when you were a five-year-old trying desperately to put a disemboweled alarm clock back together.

Of robots and gears

A Mechanical Story's gear-based puzzles revolve around an engineer that's found a defunct robot. Solving said puzzles opens up gearboxes that take you one step closer to bringing the robot back online. That's called "a good motivator."

The puzzles start off simple, as you only have two gears of varying size to mess with. Each stage is pocked with sockets that can hold those gears. By placing gears in the positions necessary to move sliders and gear racks, you can form primitive mechanisms that push buttons.

It's button-pushing that gets things done in A Mechanical Story. Stages end when your contraptions manage to push the button that frees the gear mechanism, but there's a little more to it than that. Pushing buttons can reverse gear direction, stop bearings from turning, and open up boxes containing stars.

Engineering enthusiasts will definitely want to three-star each level, so it's important to learn how to rig up your gears in a manner that successfully collects all bonuses and finishes the stage.

High score-chasers will also want to maximize their score by using as many pieces as possible. Each piece of machinery on the field increases your point multiplier.

Think harder

You don't need to be an engineer to get the gist of the puzzles in A Mechanical Story. Though the number of parts necessary to solve a puzzle gradually increases, a brief tutorial instructs you on how the new part comes into play.

If you need a refresher, you can access the tutorial videos at any time by pausing the game.

Still, A Mechanical Story is probably best suited for puzzle experts, particularly anyone with a big love for multi-step problem solving.

Its challenge is pretty hardcore, particularly since the game doesn't offer any kind of hint system. You're on your own.

Luckily, a few new levels unlock with every stage you solve, so you're never forced to mope over a single puzzle. You can move on to the next, then come back later to brush the cobwebs off your unsolved problem.

Gear up for good times

There are plenty of gear-based puzzle games out there, but A Mechanical Story's multi-part puzzles mesh with its gentle graphics and soundtrack to deliver a particularly memorable entry in the genre. Wind it up and give it a whirl.