Endless mode

Endless mode opens after you beat the final boss of the campaign. It is a full game feature.

In the game

There is no last fight here. Every win leads straight to the next enemy, and each one comes in with more health and a heavier hit than the last. The shop and the full heal between fights stay exactly as you know them. Your score is how many fights you survive, and your best streak is kept.

How it differs from the campaign

Fights are drawn from a pool of 35 enemies instead of a fixed script. An enemy that fought in the last 3 fights does not come back right away.
Every enemy is resized to the fight number, so who you draw no longer decides how hard the fight is. From fight 8 the game also starts sizing enemies against your own build, at full strength from fight 40.
From fight 6, two enemies can come at once: 15% at first, 2% more each fight, up to 60%.
Each kill pays a flat 14 gold, plus 0.2 per fight.
Kill boxes use the last level's table at 40% of its chance.
Skull rewards grow 5% per fight, up to x3.
The shop sells 1 reinforcement in place of one symbol.

Reinforcements

A reinforcement is a stat bought for the rest of the run. It does not touch your reels. They never run out: each copy of the same reinforcement is worth 10% of the base value more than the last, and costs 20% more. The price shown here is the price at fight 1; it grows with the mode's gold.