Gary's Mod

Garry's Mod was a user-made set of tools which, among much else, enabled you to pose ragdolls. The boorish humour value in doing that badly, obscenely or grotesquely has made it so hugely popular that it's nearly eclipsed the physics tinkering that actually makes the mod so wonderful. In the course of 20 successive versions of his free mod, British programming genius Garry Newman has added more and more tools to string, weld, spin, pump, winch, propel, ignite and levitate any object from the Half-Life 2 universe. All this is achieved with a Manipulator Gun and a pop-up menu: to all other intents and purposes you're playing Half- Life 2 - albeit in a weird open arena.

Other mods have tried to give creative gamers an outlet, and Garry's has beaten them at every turn by being far more intuitive, updating far more often and giving people new features they never knew they needed. That's what your £6 is getting you here: Garry's going to carry on updating this retail version for free via Steam, while version 9 (still free here) is left alone. It's also worth the asking price just to be on the same version as the majority of Garry's Mod players: jumping onto a random server exposes you to some of the most surreal, hilarious and inspired sights of any world, virtual or real.

A typical five minutes: a Combine soldier seems to be trying to make a catapult. Dr Kleiner says "Imma make a robot", summons a large metal sphere and paints eyes on it. I, as Judith Mossman, wonder if I can make a tombstone into a plasma-jet powered hoverboard. Thanks to hoverballs - a new gizmo to keep any construction stable at the altitude of your choice - it takes about 20 seconds. Kleiner attaches two long blades to his spherical friend, it takes off and starts spinning dangerously. A new player shoots my floating grave with the Duplicator gun to create a copy, and attaches a spinning blade to the front. Kleiner zooms by on a pimped-out hovering airboat, jets of flame streaming from its rear and an intent look on his bespectacled face. The Combine steps into his own catapult and is slammed straight into a support post, sending his body cartwheeling over the apex to land with a thud four feet away. The catapult catches fire.