My high school years were spent pumping thousands of hours into games like Killing Floor 2 and Team Fortress 2, so I’m glad a mod like the upcoming Mann Versus Zombies—a total conversion which turns TF2 into a zombie-blasting horde survival bonanza—didn’t come out during my high school years. I probably would not have graduated.

The details are on its Steam page, and if it weren’t for the yellow wrench banner informing me that this is a mod I might have confused it for a real spinoff. The trailer is an Source Filmmaker-powered treat, showing off some new guns as well as zombified versions of each of TF2’s iconic mercenaries as cartoony as they are macabre.

It doesn’t share any gameplay footage, just a few screenshots, but the feature list is impressive: co-op with up to eight players, unique perks, and a barricade mechanic, and endlessly scaling waves of increasingly intense difficulty. You can even wear the cosmetics you’ve snagged in the regular game—and if you’ve ever played TF2, you know that’s really all that matters.

While the new guns are a touch more grounded than the game’s standard arsenal, they strike a nice balance between tacticool and cartoonish. You’re already well-served if you want a zombie survival game from Valve or a horde mode within TF2, but this mod seems specifically excited to take TF2’s zany world in a slightly bloodier, more grim direction.

If it feels as good to play as it looks, it should be a treat for fans of the venerable shooter looking for a change of pace. That said, there’s no release window just yet.

Official updates may be infrequent (though not unheard of), but TF2 is lively as ever. Team Fortress 2 Classified, a mod which shears off many of the game’s post-launch additions and replaces them with new stuff inspired by the game’s earliest trailers, attracted thousands of players when it first launched earlier this year. Its competitive scene continues to thrive, other high-profile mods are en route, and if you can believe it, it’s still just a fun game even 19 years later.