War of the Worlds meets Sir, You Are Being Hunted in the lightly tense The Last Resistance, a small, free game where you're being hunted by a gaggle of murderous robots.
You start with nothing, alone in an atmospheric wilderness populated by skittering little spiderbots, and by giant tripods with ominous laser scanners. To survive—and, more than that, to kill all the robots—you'll need to scavenge weapons, ammo and health kits from the various bunkers strewn about. Of course, some of the bunkers require keys, while others need to be smashed open with an axe. You open each bunker in a linear order, a little disappointingly, but getting to them involves some tense sneaking and/or frantic running.
While the robots, particularly the War of the Worlds-style tripod enemies, are pretty intimidating, this is not an especially difficult game. You can move much more quickly than any of the robots, and with infinite stamina, while it's fairly easy to avoid damage by the smaller spiderbots. But the sci-fi-meets-wilderness atmosphere is striking, the stealth is initially quite tense, and the robot animations remain impressively malevolent, even when you realise they're not that deadly.
For more great free experiences, check out our roundup of the best free PC games.