Difficulty Tiers
Two new difficulties, earned per survivor. Every character starts on Normal. Beat Round 20 with them and they unlock Overdrive; do it again and they unlock System Overload. The unlock belongs to that survivor — clearing Round 20 with the Soldier does nothing for the Guardian.
Choose your difficulty before a run. The flow is now Play Game → Choose Your Survivor → Choose Your Difficulty. Locked tiers say exactly what you need to do to open them.
Harder means harder, not slower. Higher tiers raise enemy health, damage, speed and spawn density, and make the arena hazards hit harder, fire more often and cover more ground. Coin income and shop prices are identical on all three — you are not being asked to grind for the privilege.
The multipliers keep applying past Round 20, so Anomaly Mode stays as far above Normal as it was at the start.
Survivor Points
Clearing a chaos wave now pays. 1 point at Round 5, 2 at Round 10, 3 at Round 15, and 4 for beating the Core Architect — 10 for a full clear.
Three currencies: Iron, Bronze and Silver, one per difficulty, earned separately for every survivor. That is fifteen separate pools, and they persist between runs.
Points are paid when you walk into the Bazaar, so a wave you cleared is yours even if you end the run there.
Upgrade Trees
Every survivor has its own permanent tree, opened from a ⚙ Upgrades control on its character-select card — or by pressing X on a controller with that survivor highlighted. They are kept between runs and never reset.
Nodes deepen as you clear harder tiers. One node can have up to three ranks — the first bought with Iron, the second with Bronze, the third with Silver — so an upgrade keeps growing rather than being replaced by a near-identical one further out.
Each tree leans into its character. The Soldier buys options: starting coins, a second weapon, free Bazaar rerolls, a Vibe Web head start. The Guardian buys durability that turns into offence. The Scout buys the dash. The Occultist deepens its statuses. The Demolitionist buys bigger, further-reaching blasts.
Respec is free and unlimited out of a run. Nothing you spend is ever locked in.
Abilities
Three per survivor — two majors and a capstone, gated behind Overdrive and System Overload respectively.
Soldier — Stationary Fortification raises a shield when you hold position, and Combat Zone drops Tactical Beacons that speed up every weapon you fight inside them.
Guardian — Kinetic Backlash throws back a share of whatever your armour stopped, Heavy Momentum lets you barge straight through smaller enemies, and Bastion Protocol fires an EMP that freezes everything around you when you drop to critical health.
Scout — Razor Slipstream leaves a razor trail behind your dash that slows and bleeds, Slipstream Siphon turns dodges and finishing blows into bursts of speed, and Afterimage Mirage leaves a decoy that pulls enemies in and detonates.
Occultist — Soul Siphon Mark hexes what you damage so it sometimes gives something back when it dies, Blood Pact turns healing you cannot use into a shield, and Forbidden Harvest opens a vortex that drags in every drop on the floor.
Demolitionist — Combustion Core makes crits and blasts detonate the corpse, Minefield Drift leaves mines behind your dash, and Chain Meltdown makes explosions set off explosions, leaving napalm behind.
Achievements
12 new achievements — one per survivor for clearing Round 20 on each new tier, plus Full Throttle and Total Meltdown for doing it with the whole roster.
Best round and best score are now tracked separately per difficulty, so a Normal record and a System Overload record no longer compete for the same slot.
Fixes
⚠ Steam Cloud could silently delete saved progress. If two of your devices were on different versions, the older one could wipe the newer one's data for anything it had never heard of — quietly, on launch, with no error. Fixed before the new saved data shipped.
Survivor unlocks never actually synced between devices. Earning a survivor on your desktop left your laptop without it. They sync now.
Round 5/10/15 achievements were lost if you quit from the Bazaar, since they only fired when you left the shop rather than when you entered it.
The Buy Level Up button had two different prices — one deciding whether it looked affordable, another deciding what it actually charged.
Assorted fixes: resumed runs now keep their abilities and their free rerolls, the Vibe Web's controls and the new upgrade screen behave identically, and the Balance Editor gained a visual editor for the survivor trees.