The green pips under your health. Each pip swallows one incoming projectile: less than half damage and no flinch, so you keep walking through it. Specials burn two pips. Pips refill slowly on their own and much faster while you guard, and a few fighters can overfill past their maximum — that shows as a blue ring.
The yellow bar fills as you land and take hits. At full it flashes POWER READY and your fighter glows. Every fighter's special is different: beams, charges, ground slams, traps, volleys, self-repair.
Best of three rounds, 75 seconds each. Whoever has more health when the clock runs out takes the round.