SPARK 02COMBUSTIBLE

Fuel Codex

Twelve burnables from twigs to Yesterday's Sun — measured heat, phase gating, and tooltip lore.

Heat values measured on patch 1.0 launch build. "Phase" is when the fuel first appears in the shop/sky.

Fuel	Heat	Phase	Notes
Dry Twig	5	Phase I	The tutorial fuel. Feels pointless by minute ten; that's the design — the game wants you hungry.
Pinecone	12	Phase I	Pops loudly. Ten in a row triggers Popcorn Chain (see Reactions).
Old Love Letters	18	Phase I	Low heat but burns 3× longer. The first "slow burn" lesson; the tooltip says "they lasted longer than the relationship".
Wooden Chair	45	Phase I	The workhorse of phase one. Buy the yard-sale upgrade before hoarding these.
Cult Pamphlets	25	Phase II	Burning your own propaganda: +heat, +2 followers per stack. The game's politics are not subtle.
Tire	60	Phase II	Black smoke slows followers unless purified — or weaponize it (see Reactions).
Grand Piano	150	Phase II	Plays a chord as it lands. The chord is sampled; the community is trying to transcribe it.
Used Car	280	Phase II	Needs two feeders or the forklift upgrade. The horn still works mid-burn, briefly.
Tanker Truck	600	Phase II	The chain-reaction core. Alone it's just hot; with a tire it's a bomb.
Decommissioned Satellite	1,200	Phase III	Falls from the sky on its own timer — you can't buy it, only be ready for it.
Moon Chunk	5,000	Phase III	Yes, that Moon. The game stops pretending to be subtle around phase three.
Yesterday's Sun	50,000	Phase III	Secret fuel. Feed the Sun its own yesterday. How: the Reactions page. Why: the Achievements page.

"Every fuel tooltip is funnier than some games' entire scripts."
— community review