The early fights feel fairly scrappy, but a few good upgrades can push the whole run into ridiculous territory. One moment you are weaving through a crowd of slimes; moments later, the screen is buried under lightning, projectiles, explosions, and damage figures. That jump in power is where the real satisfaction comes from.
Build variety keeps the numbers from becoming the only attraction. Cards, relics, and mercenaries can pull a run in unexpected directions, especially when several bonuses happen to click together. Full version unlocked, so the complete progression loop is available from the start.