Every weapon evolves: swarmr's guaranteed 5th-pick upgrade

What shipped

Every weapon now evolves. The level-up flow gained a per-weapon level cap: four stat upgrades, then a fifth pick that is a one-time evolution. WeaponState grew level and evolved flags, and rollUpgrades became level-aware, dropping its stat cards once eligible and slotting in its evolution card.

Five evolutions landed, each a branch in an existing update*() system: Dagger becomes Thousand Fangs (three parallel daggers, 0.05s cooldown); Whip becomes Reaper (alternating front-back-front at extended reach); Garlic becomes Black Aura (1.6x radius, 3x damage); Axe becomes Cyclone (eight axes on a rotating spiral); and Laser becomes Prism (forking from each impact point). The commit also raised base laser damage from 17 to 26 and added a dev menu (backtick key) for testing each stage without grinding.

Decisions

The evolution trigger was the load-bearing decision. Vampire Survivors gates each evolution behind a specific paired passive — prerequisite pairs and a hidden recipe. Our backlog item read literally (“upgraded 5 times, then becomes something much more powerful”), so the fifth pick is the evolution. Honestly, I think VS’s paired-passive recipes are wiki-driven design — a game is better when its signature rule fits in one sentence you can learn by playing.

Two smaller calls followed. To keep RNG from burying it, a weapon’s evolution card is force-included in the level-4 roll and styled gold — chosen, not automatic — then it leaves the pool. And no evolution gets a new subsystem: each reuses its base weapon’s hitbox, so the whole feature is data plus one conditional branch.

What broke

The guaranteed-card rule collides with the three-slot roll: if several weapons reach level 4 at once, more evolution cards want a slot than exist, and the naive fill would silently drop the overflow — a player owed an evolution they never see. The fix gave guaranteed cards priority and made extras wait for the next level-up.

Prism shipped as a first cut. The doc flagged its names and numbers as placeholders, and its fork-from-impact tree was the weakest of the five; two later commits (ca1bced, 82adf93) reworked it, replacing the splitting tree with a reflecting beam. Mechanic-first, tune-second was deliberate. I’d still ship it in that order every time — you can’t balance a weapon you haven’t felt.

Numbers

No dedicated benchmark this phase — a gameplay feature gated only by the vertical slice’s frame budget: weapon work does not proceed unless the 2000-enemy target holds. Steady-state is ~1-2 ms logic and <1 ms render at 2000 enemies against a 4 ms / 8 ms budget, and the evolutions stay inside it by adding only bounded work to existing pools. The one hard number that moved is a tunable — base laser damage from 17 to 26.

Next

The immediate follow-up is the deferred balance pass, starting with Prism. Beyond that, the next phase pivots the game from a top-down arena to a side-scroller, re-aiming several evolutions downrange and forcing the Axe and Whip reworks.