The gravity gun from Half-Life 2 is a dramatically underutilized tool in games. What felt so cool and revolutionary in 2004 has since been stuck to just one game. Kind of like how there were rumblings that the portal gun would show up in a future Half-Life 2 episode, and other games with portals like Portal have popped up. Thanks to Island Delta [$1.99], it has reminded me of how clever an idea the gravity gun. But also, it serves as a reminder of how a tool that requires good physics also requires good design to be used effectively.

This is an action-physics game where you play as Zoe and Baxter, who are each equipped with gravity guns that can pick up objects and enemies, and launch them in order to achieve various tasks. You'll pick up batteries and shoot them into their proper receptacles. Crates will be stacked on top of one another to form staircases. Enemies can be defeated by launching themselves at each other or at walls. Baxter has the ability to blow stuff up, though this is used more as a story-specific ability rather than as a core gameplay element. You also have optional items to find, which can be found behind hidden switches, in boxes, and in secret areas. The core part of the fun in Island Delta is playing around with the gravity gun. Picking up an enemy and sending them to a blunt force trauma demise is entertaining, as is using robots to blow up other robots. Manipulating the world feels really cool, in a way that I wish more games did so. It's because i...