Street Fighter-style 2D fighting game: GPT-5.6 Sol

Build me a playable 2D fighting game in the browser — think Street Fighter distilled: two fighters, a health bar each, real moves and combos.

Requirements:

1. A single-screen 2D arena with two fighters facing off, each with a health bar and a round timer. Clean, characterful art (canvas or DOM sprites — animated, not static rectangles).
2. FOUR selectable characters, each visually distinct with at least one unique special move. A simple character-select screen before the fight.
3. Real fighting mechanics: move left/right, jump, crouch, light attack, heavy attack, block, and at least one special/combo (a specific input sequence — e.g. down, forward, punch — that triggers a stronger move). Implement it as a proper state machine so a character can't, say, attack while stunned.
4. Real hit detection: attacks have hitboxes, bodies have hurtboxes, blocking reduces damage, health drains on clean hits, and a round ends in KO or on timer with the higher-health fighter winning. Best-of-3 rounds.
5. Player vs CPU with basic AI (the CPU approaches, attacks in range, blocks sometimes), AND local 2-player on the same keyboard. Show the control scheme on screen.
6. Game feel: hit-pause/screen-shake on heavy hits, a KO announcement, a rematch button.

Build it, then QA: play a full best-of-3 against the CPU and a round of 2-player — confirm every move works, combos register, blocking matters, hits register only in range, and rounds/matches end correctly. Fix any broken state. Deploy live to Vercel.

DONE when: the deployed game is genuinely playable — four characters, working combos, real hit detection, and a match that plays to a winner. If moves don't register or the state machine breaks (e.g. attacking mid-hitstun), it's not done.