Stix

Stix challenges you to destroy structures while avoiding alien patrols. But be careful; a single mistake and one of these structures could become your grave. Each structure is built from sticks linked to each other by fragile connections. Travel over a connection enough times, and you will break it. When a stick is no longer connected to the rest of the structure, it will be destroyed. When the whole structure is destroyed, you will win the level. But don't let the stick that you're standing on be destroyed before then! Also, watch out for the aliens! They patrol each level, and if they catch you they will kill you.

Alternatively, if you're looking for a game that will make you think without requiring quick reflexes, you can play without aliens. Either way, it won't be easy. Stix will be a challenge, regardless of how you play.