Escape From Tarkov is the best kind of weird FPS: Eastern European. It’s a S.T.A.L.K.E.R.-style shooter made in Unity by Battlestate Games, a 40-person Russian studio that describes it both as a “realistic combat simulator” and a “first-person action RPG/simulator with MMO features.” It’ll have a dynamic in-game economy, an Elder Scrolls-style skill system where your character gets more proficient through repetition, “real-life ballistics and projectile hit physics,” as well as competitive and cooperative play with up to 16 players in decayed (but grounded) Russian industrial landscapes.

It’s unclear how this kitchen-sink approach will congeal, especially with Tarkov due in 2016, which seems relatively soon for its ambitious scope. But forget all that for now: in a pre-alpha demo of Tarkov I saw at GDC, I witnessed the most over-the-top gun customization I’ve ever seen in an FPS. It’s pure gun pornography, but my gut tells me it has a chance of creating something as uneven, eccentric, but enjoyably high-fidelity as Call of Pripyat.

The developer walking me through the demo, Nikita Buyanov, is both the COO and art director at Battlestate, who work in St. Petersberg. He pops open Tarkov’s long, scrollable inventory, which at a glance looks like, yes, a more elegant version of S.T.A.L.K.E.R.’s grid, with broken-out areas that correspond to your chest rig, pocket, and backpack contents. Buyanov pokes around, casually mentioning that Tarkov will include “the whole lineup” of AK, M4 and AR variants at release, along with other shotguns, pistols, and others, amounting to “nearly 200 guns,” all real-world weapons.

Before I can prod him more about the gun roster, Buyanov opens the modification menu for his AK-74, which magnifies the weapon into a generous, fullscreen view that reminds me of Crysis. Nine lines denote modification points for the weapon: receiver, magazine, grip, stock, magazine, muzzle, and a few others. He slaps a rail system to the front of the weapon and the number of modification points doubles to 18 (watch at 3:08 of the video above). I’m not sure what they all correspond to, but there sure are a lot of them.

Tarkov will include “the whole lineup” of AK, M4 and AR variants at release, nearly 200 guns.

Then Buyanov does something bizarre: he rips the dust cover off an AK-74—the top ‘spine’ of the rifle that protects its moving parts from debris. With the cover still off, he exits back into the factory scene we’re in and fires away. The weapon works fine, but its guts are exposed, and you can see its internal piston kicking and bobbing as he spams the trigger. I’m pleased to hear that this apparently isn’t just a pointless cosmetic change, but something that’ll actually make this AK degrade more quickly, and make it more prone to jamming. And by removing components like the stock, the AK takes up less room in your inventory.

Then Buyanov does something even weirder: he digs deeper into the inventory and finds a 90-round drum magazine. Which he loads into a Makarov pistol.

It’s the sort of thing a firearms YouTuber makes a novelty video of. He plugs away with the Makarov, emptying the cylinder, then pulling out the absurd bullet-scrotum, which is fully twice the size of the wimpy Russian pistol. Reloading itself will have some nuance, too: double-tapping R triggers a tactical reload, which throws your mag to the ground instead of returning it to your inventory, saving you a second or two before a fresh one is slapped in. Mags that are abandoned this way are dropped in-place and can be retrieved later.

Tarkov’s structure is still opaque to me—I wasn’t shown a world that was populated by NPCs or quests, so I have no clue how or whether this system will meaningfully feed into the rest of its experience. For now, its weapon modding is legitimately insane—if there’s as much fidelity at the other end of its guns, Tarkov could be a gritty, surprising thing.