// In LevelEventManager.java - updateZONE() method
private void updateZONE() {
    if (currentAct != 1) return;  // Act 2 only

    switch (eventRoutine) {
        case 0 -> {
            // Wait for approach trigger
            if (camera.getX() >= APPROACH_TRIGGER_X) {
                camera.setMinX(camera.getX());
                camera.setMaxYTarget((short) ARENA_MAX_Y);
                eventRoutine += 2;
            }
        }
        case 2 -> {
            // Lock arena and start spawn delay
            if (camera.getX() >= ARENA_LOCK_X) {
                camera.setMinX((short) ARENA_MIN_X);
                camera.setMaxX((short) ARENA_MAX_X);
                eventRoutine += 2;
                bossSpawnDelay = 0;
                AudioManager.getInstance().fadeOutMusic();
                GameServices.gameState().setCurrentBossId(BOSS_ID);
            }
        }
        case 4 -> {
            // Lock floor and spawn boss after delay
            if (camera.getY() >= ARENA_FLOOR_Y) {
                camera.setMinY((short) ARENA_FLOOR_Y);
            }
            bossSpawnDelay++;
            if (bossSpawnDelay >= 0x5A) {  // 90 frames
                spawnBoss();
                eventRoutine += 2;
                AudioManager.getInstance().playMusic(Sonic2AudioConstants.MUS_BOSS);
            }
        }
        case 6 -> {
            // Prevent backtracking during fight
            if (camera.getX() > camera.getMinX()) {
                camera.setMinX(camera.getX());
            }
        }
    }
}

package uk.co.jamesj999.sonic.game.sonic2.objects.bosses;

public class Sonic2ZoneBossInstance extends AbstractBossInstance {

    // State machine constants (ROM: routine_secondary values)
    private static final int SUB0_APPROACH = 0x00;
    private static final int SUB2_ACTIVE = 0x02;
    private static final int SUB4_ATTACK = 0x04;
    private static final int SUB6_DEFEATED = 0x06;
    private static final int SUB8_FLEEING = 0x08;

    // Position/velocity constants from disassembly
    private static final int MAIN_START_X = 0xXXXX;
    private static final int MAIN_START_Y = 0xXXXX;

    public Sonic2ZoneBossInstance(ObjectSpawn spawn, LevelManager levelManager) {
        super(spawn, levelManager, "Zone Boss");
    }

    @Override
    protected void initializeBossState() {
        state.x = MAIN_START_X;
        state.y = MAIN_START_Y;
        state.routineSecondary = SUB0_APPROACH;
        spawnChildComponents();
    }

    @Override
    protected void updateBossLogic(int frameCounter, AbstractPlayableSprite player) {
        switch (state.routineSecondary) {
            case SUB0_APPROACH -> updateApproach();
            case SUB2_ACTIVE -> updateActiveBattle(player);
            // ... other states
        }
    }

    @Override protected int getInitialHitCount() { return 8; }
    @Override protected int getCollisionSizeIndex() { return 0x0F; }
    @Override protected void onHitTaken(int remainingHits) { /* hit reaction */ }
    @Override protected void onDefeatStarted() { /* transition to defeat state */ }
}

public class BossChildName extends AbstractBossChild {

    public BossChildName(Sonic2ZoneBossInstance parent) {
        super(parent, "Child Name", priority, Sonic2ObjectIds.BOSS_ID);
    }

    @Override
    public void update(int frameCounter, AbstractPlayableSprite player) {
        if (!shouldUpdate(frameCounter)) return;
        syncPositionWithParent();
        // Child-specific logic
        updateDynamicSpawn();
    }

    @Override
    public void appendRenderCommands(List<GLCommand> commands) {
        // Render relative to parent position
    }
}

registerFactory(Sonic2ObjectIds.ZONE_BOSS,
    (spawn, registry) -> new Sonic2ZoneBossInstance(spawn, LevelManager.getInstance()));

Review the implementation of [ZoneName] Boss (0xXX) against the Sonic 2 disassembly.

Reference: Use the s2disasm-guide skill for disassembly navigation guidance.

Files to review:
- [List all created/modified files]

Disassembly references:
- Boss object: docs/s2disasm/ObjXX...
- Level events: docs/s2disasm/LevEvents...

Validation checklist:
1. LevelEventManager arena setup matches LevEvents_ZONE2
2. State machine transitions match routine_secondary values
3. All child components spawned correctly
4. Hit count and invulnerability timing match ROM
5. Defeat sequence (explosions, flee, EggPrison) matches ROM
6. Art and mappings render correctly
7. Music transitions (fade, boss music, resume) work correctly
8. Camera boundaries lock/unlock correctly
9. No TODOs or simplifications
10. No "engine limitation" workarounds

Report any discrepancies with specific line references from both code and disassembly.