Left and Right: Move
Space: Press once to jump, twice to double jump, three times to smash the ground. Hold space to float.
Down or S: Use focus (your next attack will smash the ground harder, you'll do double damage, you'll hurt blocking enemies)
While floating, you can absorb enemy shots. If you absorb 3 shots and release float, you will retaliate with one of three powerful spells. Absorb 8 shots (without touching the ground) and you'll release one of three REALLY powerful spells.
While floating, you'll be boosted upwards (and thus can float longer) if you grab any powerups mid-air or absorb any shots.