Protostar

Collapse matter into a star.

A deckbuilder where every run forges a star — and you get to keep your stars in your galaxy.

Protostar is a cosmic card roguelike deckbuilder. Fuse matter and density into Formations, Collapse them for Flux × Multiplier, and spend Ember on Principles — your scoring engine. Ignite a star, keep it in a living galaxy, and climb the ascension ladder.

How it plays

You are a collapsing cloud of matter on the edge of becoming a star. Draw cards, match matter and density into Formations, and Collapse them for Flux × Multiplier toward each encounter's radiance threshold. Spend Ember in the Singularity shop on Principles, and lean into a direction: same-family Harmony tiers, retriggers, run-scaling banks, molecule chemistry, the Iron-core sink, and ×-multiplier capstones. The shop even steers toward the build you commit to, so a chosen path is one you can actually assemble.

Ignite & keep your stars

Clear the run to Stellarize into a real star, classified on an HR diagram by how you played — then left behind in a persistent galaxy you can name, that grows run after run. Push past the standard run into red-giant territory to earn neutron stars and black holes; fuse two objects into a supermassive core. Win or lose, every run leaves its mark. Climb the 9-tier ascension ladder, face 13 anomaly bosses that each rewrite a rule of the encounter, and unlock Remnants, Sparks and Cores that reshape the next attempt.

What's in the box

100 Principles · 17 Formations · 20 Sparks · 13 anomaly bosses · 14 Remnants · 9 ascension tiers · 4 starting Cores — and more to come.

Join the community

Have 2 minutes? Your feedback shapes the next build: give feedback here.

Discord: discord.gg/f6M6g3zHB