You're a bomb that throws bombs. For GMTK Game Jam 2026 I built Time Bomb Miner, a round-based roguelike where you play as a live explosive digging through a procedurally generated hex mine. You race your own countdown to find the best spot to detonate, chaining explosions through ore veins, mining out hardened vaults and dodging lava before your fuse runs out. Whatever the blast destroys turns into coins, which get spent on upgrades between rounds as the quota climbs higher each time. I did the design and programming, the hexagon tileset art is by Scir.
Ranked from 31 ratings, out of 10,500 entries and 223,000 ratings across the whole jam. Score is adjusted from raw score by the median number of ratings per game in the jam.
| Enjoyment | Creativity | Artwork | Narrative | Audio | |
|---|---|---|---|---|---|
| Rank | #222 | #1215 | #2296 | #5499 | #9118 |
| Score | 4.161 | 3.968 | 3.613 | 2.258 | 1.645 |
The core gameplay loop
Every round starts the same way: you spawn at the center of a procedurally generated mine with a ticking fuse. Walking costs time, and the ore worth the most is far out there. So: find the best spot to explode when the timer reaches 0! Whatever terrain is caught in the blast turns into coins, which have to add up to that round's quota or the run ends. Between rounds a shop lets you spend everything you dug up on permanent upgrades, and the quota goes up for the next round. Upgrades provide you with items like extra bombs you can throw, or unlock permanent abilities like a locator circle to find the rarest ore types and items.
A hex grid built to explode
The mine is a flat-top hex grid instead of the more obvious square grid, mainly because it just looks better, but also because explosions and chain reactions feel nicer when every neighboring tile is the same distance away.
Godot's TileMapLayer has built-in hex support, but getting it to actually behave took some trial and error.
The two values that matter are tile_offset_axis = VERTICAL and the exact pixel tile_size of the source art.
Stone has two weighted visual variants so adjacent tiles don't look like copies of each other. Tile definitions control HP values, coin value and more.
Procedural generation
Each mine is built by running a fixed sequence of generator passes over the grid, each one reading and writing to the same tilemap. Simplex noise carves out cavern blobs, a second "spaghetti" pass connects them with winding tunnels, and a distance-from-center map (computed once via hex breadth-first search) lets every later pass bias itself toward or away from spawn.
Every ore has its own generator instead of one shared algorithm with different knobs. Coal scatters as loose dots, gold grows in dense clumps with a few gaps so it doesn't read as a solid hex, fluorite walks in straight seams along a hex axis. Rarer ores get pushed further out using the same distance map. The spawn room is carved wherever already has the most open space nearby instead of always sitting dead-center, so no two mines open the same way, and a final pass stamps an indestructible boundary around the whole map, always running last so nothing can dig through it.
Features and Structures
On top of the ore passes, the mine seeds a pool of features and custom structures. Vaults are rotated rooms walled in the hardest stone with ore packed inside, there are hardened lava vaults that are surrounded by a moat of lava with one sealed door, and craters ring a hard stone core with structure-ore. A few bigger ones scale that up further: a Grand Cavern is one huge open cave with boulders and mixed ore, a Rift is a long hazardous canyon with a hard-stone vein down its middle. There's also a mineshaft, a wood-lined tunnel that branches into dead ends and loops instead of running straight, with a secret item hidden in one of its rooms! It's a cloak that lets you walk over lava! Get it first each round to reach all valuable ores.
Chain reactions
Explosions aren't a flat area-of-effect circle. Each explosion fires rays outward in every direction as a simulation stepped frame by frame, and every ray reduces the HP of whatever tile it hits until either the tile breaks or the ray runs out of force. The randomly distributed rays and the denser rock thus shape the blast interestingly instead of every explosion looking the same.
The Chain Reaction ore uses this directly: it's placed as a sparse, winding line along cave walls, and destroying one tile drops a bomb in its place with a short fuse.
Four days, not much sleep
I built this over one jam weekend, working in whatever spare time we found while I was traveling. Audio was the first thing to go once the deadline got close, and it's the one thing almost every comment on the jam page mentions. That's the first thing I want to add if there's a post-jam update. Balancing is the other loose end. Most of the values feel fine for a jam entry, but it's too easy to reach the quota early on, and it only really gets challenging (and then very quickly impossible) around round 39 or so.
Users
How am I the first person to comment on this?? This is one of my favorite games I've played so far from the jam. Great game juice with the screen vibration and explosion animations. Reminds me of Minecraft to a degree with searching for ores. For just 4 days this game is super impressive!
Dude, I saw your game on Discord, and I liked it so much and got so hooked that I played about 20 rounds in a row without a break.
This game is the most time I've spent on a game this jam! Completely enjoyable. Unbelievable you did such amazing work in just four days.
A bomb that throws bombs? Genius. Why didn't I think of that?
Nice, I like the dual pressure of finding good places for your bombs and exploring while also making sure wherever you eventually detonate is ore-rich. I liked hunting down the lava cloak, I think if you develop it further, more artifacts to find would be a highlight.
The potential is really there. The explosion is jiggly and satisfying, and the progress is noticeable. The missing sounds is really a bummer though, would have made this so much better.