Mesozoic Protocol

A single-player roguelite tower defense where you pilot a hero mech alongside your turrets and hold thirty outposts against waves of dinosaurs and matriarch queens.

Mesozoic Protocol is a single-player roguelite tower defense from Ricos Labs LLC, the studio of solo developer Rico Trebeljahr. Pick a hero mech, place six tower types, and hold thirty research outposts against waves of reanimated dinosaurs and biome-themed matriarch queens. Four heroes — George, Leela, Mike, Stan — each with a kit of four active abilities, unlock as you accrue bolts dropped per kill. Heroic and Containment level modifiers turn each clear into a five-star puzzle. The full campaign is free to play in any modern browser at play.mesozoicprotocol.com, with no ads and no microtransactions. Desktop builds for Windows, macOS, and Linux, plus iOS and Android versions, are in preparation.

Mesozoic Protocol is a single-player roguelite tower defense from Ricos Labs LLC, the studio of solo developer Rico Trebeljahr. Players take the role of an operator at a revival-biotech outpost where containment has very much failed: the cloning rigs are still running inside the perimeter, and the specimens have integrated the revival hardware into themselves. From a fixed top-down camera, the player pilots a hero mech alongside chains of sci-fi turrets and holds the line through six biomes and thirty hand-designed outposts.

The game pairs two layers that most TDs keep separate. The tower layer is six classic-feeling kinds — Pulse, Chain, Cryo, Mortar, Pyre (flame), and Hive (drone support that buffs adjacent turrets) — each with two upgrade paths and three tiers, plus a persistent meta-skill tree per tower kind. The hero layer is four piloted mechs, each with four active abilities — dash, burst, self-buff, pilot-specific ultimate — unlocked with bolts, the in-game scrap currency dropped per enemy kill: George (kinetic sniper) at 0 bolts, Leela (electric skirmisher) at 250, Mike (flame) at 600, Stan (heavy artillery) at 1,200. Pilot ultimates are distinct: George's Bullet Storm (fire-rate frenzy), Leela's Storm Surge (self-AoE chain lightning), Mike's Inferno Ring (expanding flame waves), Stan's Annihilator Missile (single huge warhead). Bosses are six biome-themed matriarch queens — raptor, stego, para, allosaur, armored, and the apex apatosaur — each with her own model, resistance profile, and child-spawn stream. Heroic and Containment level modifiers stack extra stars on top of the base three-star grade.

The full campaign is free to play in any modern browser at play.mesozoicprotocol.com — no ads, no microtransactions, no accounts. Desktop builds for Windows, macOS, and Linux, plus iOS and Android ports, are in preparation, with planned single-tier pricing of $6.99 on desktop storefronts and $3.99 on mobile.

I built Mesozoic Protocol because the tower defense genre is starved for asymmetric enemies and starved for a reason to keep the player acting between waves. There are hundreds of TDs and most of them have generic fantasy goblins, and most of them ask the player to watch instead of act.

The hero mech is the answer to both. You're piloting one of four heroes with four active abilities — dash, burst, self-buff, pilot-specific ultimate — alongside your towers, in real time, on the same map. Heroes unlock with bolts dropped per kill — so the hero shop is the meta loop and the level grind is what feeds it.

Bosses are biome-themed matriarchs. The raptor queen sheds juvenile swarms behind her as she runs. The stego matriarch calves a stego every few seconds. The parasaur resonator amplifies chain damage. The apex apatosaur at level 30 is the final-wave threat — cold is the only real lever against her. Six queens, six biomes, every encounter a different shape.

I'm building this solo with TypeScript, React Three Fiber, Vite, and Tauri. The web build is the canonical version. Audio and 3D assets are licensed from indie marketplaces; everything else is hand-built.

— Rico Trebeljahr