I Only Moved My Mouse

Your mouse cursor is the blade. Every monster it passes through is cut.
Wave after wave, sweep through the horde and defend the crystal at the center to the end.
Forty weapons, starting with the sword, and each one cuts its own way. During a run you can socket two more beside the one in hand, and all three cast their own skills.

Slam, bat, cleave

The hammer drops at the crystal's foot and shock rings roll out, the monster nearest the crystal is batted into the crowd behind it, and a huge blade splits the floor in a long cleave that knocks the crowd back.
A warhammer in hand, a war club and a greatsword in the sockets: HAMMERFALL, HOME RUN, EARTHSPLITTER, all three cards maxed, the top level a weapon's card reaches in a run.

Three into one: TRIAD awakenings

During a run you build a hand of awakening cards, drafting one from three at a time. Now and then a TRIAD is dealt on its own: a MYTHIC card that wakes cards from three schools as one, whether you hold them or not.
Take GALLOWS STORM, one of the three TRIADs, and DEATHMARK (itself two cards fused) and ARC go off as one, and every mark the cut passes on rides the bolt to five more. A TRIAD is a gift: the wave's own draft still follows it.

Fire and stone

A wavy flaming blade sweeps a burning band, flail heads fall from above on the thickest crowds, and stones pelt monsters all over the floor.
A flamberge in hand, a flail and a sling in the sockets: FLAME WAVE, COMET FALL, STONE HAIL, all three cards maxed.

Rings of steel

A scythe sweeps a full turn round the crystal, halberd heads rise in a ring around the crystal and stab, and a chakram ricochets from monster to monster.
With a scythe in hand and a halberd and a chakram socketed, REAPING CIRCLE, PIKE RING and RICOCHET RING all have their cards maxed.

Crescents

Crescent waves sweep outward in an arc, a crescent blade circles the crystal as far out as your cursor, and a sand-gold slash fans out wide.
A sickle in hand, a bardiche and a khopesh in the sockets: HARVEST MOON, CRESCENT MOON, DUNE CUT, all three maxed once more.

Storm

Every blow your sword lands leaps on as lightning, and when one of the monsters bound by a thread takes a hit, every other one feels a share of it. A sign drawn with the blade rises as a thorned post that throws its ring out and draws it shut, crushing harder the more it caught.
LIVE WIRE and TETHER cast from the skill bar, a NOOSE drawn with the blade, JOLT, STORMROD and ARC from the awakenings, and on top of it all the crossbow's BOLT STORM with its card maxed.

What resets, what stays

Progress builds in three layers: one starts over every run, one at every melt, and one never.

Each run starts fresh. You draft awakening cards from scratch again, one from three at a time, up to ninety-nine in a run, and the weapons that come into the two empty sockets climb from LV 1 again. When the crystal breaks, your hand of cards is gone, but nothing you picked up is lost: shards go to the bank, gear to your bag, and the experience is already yours, so even a run that broke early leaves you stronger.

Each melt starts the forge over. Between runs your banked shards buy upgrades along the forge's seven rows and raise the sword's tier from Chipped Iron to Godsteel; when the climb slows, melt the sword. Its tier goes back to one and the forge and the bank empty, but the melt pays embers: the further your runs reached and the higher the sword stood, the more. Embers buy relics rank by rank, and the ranks stay. Right after a melt, before your next run or forge purchase, you may also hand relics back for every ember they cost and spend them another way.

Everything else is yours for good. No melt takes:

• your level, up to 3000, and every skill point it paid
  
• your skill tree: 28 nodes holding nine player skills
  
• your signs, five shapes drawn with the blade
  
• your level cards, sixty in all: three picks every level, and each card you pick again climbs a rank, up to rank 30
  
• your relics, 39 in all, and every rank you bought
  
• your gear: sixteen slots, seven rarities, eighteen uniques
  
• every weapon you have won, thirty-nine beside the sword
  
• every theme you have opened, thirteen in all
  
• your achievements, 46 in all, and the bonus each one pays

So a melt is never a loss: it trades the sword's tier for relics that never leave, the next climb is faster than the last, and what stays only grows with every run.