Free 3D platform fighter · Steam playtest
SLOPArena
Smash-style chaos in 3D. Build damage, send your friends flying, argue about balance.
Access is by request: Steam emails you when your spot opens.
What is this?
Smash rules. 3D arenas. Friends, airborne.
SLOPArena is a free platform fighter played in full 3D. Hit people to build their damage. The higher it gets, the farther they fly. Knock them out of the arena to take a stock. Last one standing wins.
Damage = distance
Every hit raises your percent. At 0% you shrug it off. At 150% a sneeze sends you into orbit.
Twelve moves, one grid
Every fighter gets eight normals (1–4, on the ground and in the air) and four specials on cooldowns (A, E, R, F). Learn one, read them all.
Rooms for up to four
Make a room, bring friends, fight, rematch. The netcode is still mid-surgery, so expect weirdness and please report it.
Free and open source
Free on Steam, MIT-licensed on GitHub. Built by one developer with AI agents, asset packs and questionable decisions.
The roster
Pick your poison.
Four fighters, each with eight normals and four specials. Every kit is still being tuned, so your main might get nerfed by Tuesday.
FightGuy
The all-rounder
The underground champion, and very pleased about it. FightGuy backs up the grin with quick punches, flying kicks and blue ki. A straightforward all-rounder with a show-off streak.
Must try FFist of Fury
Manki
The mad bomber monkey
A pyromaniac monkey with a jetpack and no safety training. Manki lobs bombs, fires a bazooka, sets the air on fire and floats out of trouble.
Must try RBazooka
Wibou
The sword duelist
Shades, katana and far too much anime. Wibou is a mall ninja with green hacker effects and the fastest run in the roster. Keep people at sword’s reach, cut through a gap, then send them up and straight back down.
Must try FSkyfall
Bonk
The big hitter
A good-natured brute with a bucket helmet and a very big swing. Bonk wants to be a hero, protects anyone smaller than him and occasionally rings his own head. Slow feet, huge jumps, simple plans: BONK!
Must try RCharging Double Slash
Stages
Six stages. No safety inspections.
Rooftops, boats, birthday cakes. Every stage is a 3D arena with edges to fall off and blast zones to fly into.
Slop Pit
The original fight pit. Crowd included.
After Hours
A neon rooftop. SLOPArena tonight.
Splash Deck
A boat off the coast. Mind the edge.
Table Manners
A birthday cake in a kid’s bedroom. Don’t ask.
Last Stop
A station roof. Missed your train anyway.
Log Off
A tree stump at a campsite. No Wi-Fi, just logs.
How to get in
Get in the slop.
Request access
Open SLOPArena on Steam and hit Request Access under “Join the SLOPArena Playtest”. It’s free.
Watch your inbox
Steam emails you when the next wave of testers gets in. Wishlist the game while you’re there.
Install and fight
Find SLOPArena Playtest in your Steam library. Windows, with keyboard and mouse or a controller.
After the match
How was the slop?
Played a match? Tell me what broke, what felt great and who needs a nerf. One sentence is enough, and it goes straight to the developer.
Behind the slop
One dev. A pile of AI agents. All of it open source.
SLOPArena is built in the open: Unity 6, a deterministic C# simulation shared by the game and its servers, and public workflows for the AI agents that help build it.
How SLOPArena is made
One developer, one deterministic simulation, a pile of AI agents and a playtest loop. The workflow behind the game.
Read →Making Nyx in a day
One evening of concept art, one day of agents. How Nyx went from a goth-girl idea to a playable two-form fighter, every prompt and mistake on one timeline, and the tools that let dozens of agents share one Unity Editor.
Read →Under the hood
How a SLOPArena match runs. One deterministic simulation, an authoritative server, prediction and rollback, and rooms instead of queues.
Read →