Half-Life is chock full of horror, so figuring out the ‘most terrifying moment’ is a toughie. It’s either the stalker train crash in Episode One or that horrifying headcrab bombardment at the start of Route Kanal. Seeing someone helplessly trying to wriggle one off their head before going limp while what looks like an undercooked rotisserie chicken continues pulsating gave me nightmares as a kid. The best (or perhaps, worst) is the stretch of sand where one wrong step will see you hounded by antlions lurking underneath. It’s not the same kind of body horror that normally makes Half-Life sickeningly creepy, it’s a tense kind of fear - the kind where you’re on edge the whole time, tiptoeing across a barren wasteland.

It all starts after you ditch the jeep. There’s a man lying on the sand, fatally wounded, with his friend on a rock beside him, trying desperately to save him. As you walk by, he yells at you to stay on the rocks and, importantly, not to step on the sand. That’s key. And to show you that it's key, Laszlo starts wriggling and an angry pack of enlarged alien bugs, antlions, come out and maul him to death. For one, gross. But also, that’s terrifying.

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I remember this level vividly, and even though I got the attached achievement (complete it without stepping on the sand, just as Laszlo’s friend asked), I still try my best in each and every playthrough to get across without aimlessly sprinting and shoving everything away with the gravity gun. That’s because it’s Half-Life 2’s most impressive puzzle. It mixes the usual physics antics with its signature horror, only in place of uncanny human experiments and parasitical nightmares, it’s a giant spider web made out of sand. If you hit even a grain, you trigger the hive, sending signals to the lurking creatures below that rip out of their caverns to tear you limb from limb. It’s like stepping foot onto a beach full of crabs, except the crabs are spiders as big as dogs.

The physics puzzle comes from how you get across the sand. It’s not a case of hopping from rock to rock. They’re too spread out. You have to place objects and create paths, but there aren’t enough objects to make complete bridges. Instead, you have to pull the piece behind you and place it in front of you, cutting off your way back to the start. And while it’s an open dune with your goal in sight the whole time, there are little pockets dotted about full of ammo and gear. You’ll need that equipment given that, once you cross this patch of sand, you’ll be fighting the giant headbutting antlion boss—so not only are you creating paths to the end, but to the left and right along the way, constantly backtracking as you make your way across.

It’s the perfect kind of horror, playing on classic childhood fears and games. We’ve all played The Floor is Lava at some point. Only the floor isn’t lava, it’s a spider’s web that will eat you - I’ll take the lava, thanks.

Don’t step on the sand. That’s all it is. That’s what we’re told the second we arrive, and it’s one of the few things we hear from the NPC standing on the rock. You can tempt him and risk it, but he will die and you’ll end up fending off a pack of angry antlions that might just shove you back onto the sand where you’ll alert even more.

I’m not sure if it’s the ‘most terrifying moment’ in Half-Life, but it’s the one that sticks out most of all to me, the level I’ll occasionally stick on even if I have no intention of playing the entire game. It’s a great way to play with Half-Life’s physics while getting immersed in its freaky world of horrors, and sums up the ways in which it’s far more than just another FPS, so it’s no wonder that it’s the moment that leaps out to me. I’m just sorry I got Laszlo's friend killed so much as a kid. I’m still making it up to you, bud.

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