Visit a waterpark and you’ve gotta assume someone has peed in the pool. Lots of someones, actually. Soaking in anonymous wee is just the price you pay for an afternoon of waterslides and river rafting.

But at Water Station One, billed as “the galaxy’s most unregulated waterpark,” a little bit of pee had some major consequences.

“Since the waterpark is on a space station they can only use special space water,” Lazy River creator Mike Boxleiter explained at Day of the Devs. “Because of the special properties of space water you should not pee in the pool. If you do pee in the pool, the pee will go back up into you and turn you and everyone else in the water into zombies.”

Everyone get that? No follow-up questions? Good. It’s basic space water science, people.

In Lazy River, everyone in the park has been turned into zombies by pee except you and your friends, who now need to escape the outbreak by rafting down the park’s river ride. That means building your own raft from scavenged resources, arming yourself with weapons like water cannons and pool noodles, and fighting your way through the park’s automated defenses.

It looks like a silly good time: cartoony Left 4 Dead vibes mixed with survival crafting and ragdoll physics. Cobble together a raft from inner tubes, arm yourselves with water pistols, cook some hot dogs on the grill to keep your health up, and gather what you can find on land before scurrying back to your mobile base as the zeds swarm you again.

Even on your raft, you’re not completely safe. “You’re gonna get hop-ons,” Boxleiter said gravely. As you travel down the river you’ll eventually build your humble raft up into a floating fortress, and you’ll need it: the park’s robotic defenses want to contain the zombie outbreak—and you and your friends with it.

It looks like a lot of fun, but don’t put your swimsuit on just yet: Lazy River isn’t coming to early access until 2027. In the meantime, here’s its page on Steam.