DIG. OUTSMART. BRAWL.

TAKE YOURRIVALRYUNDERGROUND.

Official key art

Two tanks. Uncharted ground. Your own way through. Dig, hunt and fight in a world where you carve the battlefield.

View on Steam Be part of the alpha

Coming to Steam · Store page preparing to open

An indie game by Josef “Chose” Šíma

Meet your next rivalryIn development · Alpha

Official key art

1 vs 1Head-to-head tank combat

FIRST TO 3Every takedown counts

8 MINOne more round?

PC · MAC · LINUXBuilt for Steam

01 / THE GAME

NO PATH?MAKE ONE.

The best route to your opponent is the one they never saw coming.

Carve your battlefield.

Dig through earth, work around solid rock and leave a network of tunnels behind you. Every route opens an opportunity. Or a way for your opponent to find you.

Spend your energy wisely.

Fast digging and cannon fire draw from the same energy pool. Push your attack, or save enough to make it home. Your base repairs your shield and gets you back in the fight.

Hunt. Adapt. Rematch.

Explore the darkness and find your rival. The first to three takedowns wins, with an eight-minute limit. When the match ends, the full map reveals the story of your duel.

INSIDE THE ALPHAReal gameplay captures · Work in progress

02 / THE INSPIRATION

SOME GAMESSTAY WITH YOU.

Two friends. One keyboard. And a whole world underneath the surface.

As a kid, I spent hours playing Tunneler, the DOS tank game by Geoffrey Silverton. Digging through the dark, finding a friend’s tunnel, then deciding whether to follow it. That feeling never really left.

Tunnel Brawl is my way of chasing that feeling again, with a new world, modern online combat and a game I have always wanted to make.

Meet the original Tunneler

TUNNELER

THE BEGINNING

A childhood spent digging tunnels.

2024

The first prototype. The first devlog.

2026

A fresh start. Unity. Steam. Alpha.

An independent game inspired by Tunneler. All its own identity.

Josef “Chose” Šíma, the indie developer behind Tunnel Brawl — **JOSEF “CHOSE” ŠÍMA**Developer & founder of Supro Nivelo

03 / THE DEVELOPER

ONE DEVELOPER.A LONG-HELD DREAM.

Hey, I’m Chose.

I’m Josef Šíma, a developer, product designer and former CTO from the Czech Republic. I’ve spent over 20 years building software, with chapters at Seznam.cz, Woltair and Groupon. Making my own game has been the dream running quietly in the background.

Tunnel Brawl is my indie project. I make the game and publish it through my company, Supro Nivelo. And yes — the company is just me, too.

Meet Supro Nivelo LinkedIn

04 / THE DEVLOG

BUILT IN THE OPEN.

The decisions, detours and small victories behind the game. Written by me, published on Medium.

Follow on Medium

LATEST CHAPTER / THE RESTART

10 Sept 2026 MEDIUM · EN

I promised a game in 6 months. It took me 20 months to write the next blog post.

Twenty months later: why I stopped, what brought me back, and how Tunnel Brawl became a playable Unity alpha.

Read on Medium

FROM THE ARCHIVE / 2024

These posts document the original browser prototype. Today’s alpha is a new game built in Unity.

11 Dec 2024MEDIUM · EN

How to properly develop multiplayer game

Learning why the server needs to be the source of truth in a multiplayer game.

09–10

1 Dec 2024MEDIUM · EN

Major server-side refactoring

Taking the early server apart and giving the growing game a more solid foundation.

19 Nov 2024MEDIUM · EN

Baby steps in multiplayer

Connecting the pieces and taking the first steps toward real multiplayer.

Explore all 10 archive articles

12 Nov 2024MEDIUM · EN

How to manage shared state in Svelte 5 with runes

Finding a way to share application state across the original game interface.

05–06

3 Nov 2024MEDIUM · EN

Login and registration of player and WebSockets connection to right server

Player accounts and the journey from login to the correct game server.

20 Oct 2024MEDIUM · EN

First UI and database decisions

Early interface work and choosing where the game’s data should live.

13 Oct 2024MEDIUM · EN

Building the WebSocket Server

Building the connection between players and the first game server.

6 Oct 2024MEDIUM · EN

Refactoring the POC

Cleaning up the proof of concept after a first week of experimentation.

29 Sept 2024MEDIUM · EN

Proof of Concept (POC) and ECS

The first week: making a small idea move on screen.

22 Sept 2024MEDIUM · EN

Build a complete game in 6 months as a side hustle

A childhood favourite, an ambitious promise and the beginning of Tunnel Brawl.

05 / COME UNDERGROUND

SMALL GAME.BIG ON RIVALRIES.

The alpha needs curious players, honest feedback and a few good rivals. Join the Tunnel Brawl Discord to arrange playtests, share progress and help me build a better game.

Join the Discord

Start in #start-here. I coordinate alpha access and playtests personally. English and Czech are welcome.

Follow on Medium

Still digging. Still building. See you underground.