Challenges

Create a complete Vampire Survivors-style survival arena game as a single self-contained HTML file.

REQUIRED FEATURES:
1. Canvas-based rendering, full-window (or 800x600 minimum)
2. Player character: drawn as a small humanoid with weapon visual (whip/sword/staff rotating around)
3. Movement: WASD / Arrow keys, at constant speed (no acceleration)
4. Touch controls: virtual joystick (left half of screen for movement)
5. Auto-attack: weapon attacks automatically toward nearest enemy (invisible targeting, no aim required)
6. Initial weapon: Magic Bolt — shoots a projectile at nearest enemy every 2 seconds
7. Enemies spawn continuously from screen edges (outside visible area, move toward player)
8. Enemy types:
   - Bat (fast, low HP, 10 XP) — spawns from start
   - Skeleton (medium speed, medium HP, 25 XP) — from 1-minute mark
   - Ghost (phases through other enemies, 15 XP) — from 2-minute mark
   - Werewolf (slow, high HP, 50 XP, charges) — from 3-minute mark
   - Boss giant (spawns every 5 minutes, huge HP, 200 XP, AoE attack) — from 5-minute mark
9. Enemy scaling: spawn rate increases over time, enemy HP scales with time played
10. XP gems dropped by enemies (float toward player, auto-collect when close)
11. Level up: every 100 XP, game pauses and shows 3 random upgrade choices
12. Upgrade pool (choose 1 of 3 each level up):
    - Magic Bolt +1 level (more damage, faster fire rate)
    - Fire Wand (unlock: fires piercing fireball)
    - Holy Water (unlock: leaves damaging zone on ground)
    - Garlic (unlock: AoE damage around player)
    - Speed Up (+10% move speed)
    - Max HP Up (+20 HP)
    - Armor (-1 damage taken)
    - Magnet (+30% XP pickup range)
    - Projectile Speed (+20%)
    - Area (+15% weapon area)
    - Weapon evolutions at max level (e.g., Magic Bolt Lv8 → Thunder Loop)
13. Player has HP bar (starts at 100). Contact with enemy = damage. Brief invincibility after hit (0.5s flashing).
14. Timer display (minutes:seconds) counting up — goal is to survive as long as possible
15. Score = XP collected + time bonus
16. "Game Over" when HP reaches 0: shows survival time, level reached, enemies killed, score
17. Start screen: title "SURVIVOR" + "Press any key to start" + controls

AUDIO:
18. Web Audio API: XP collect (soft chime), level up (ascending fanfare), hit (thud), enemy death (pop), boss spawn (deep horn), game over
19. Optional: simple background beat (low-fi loop with oscillator percussion)

VISUAL:
20. Dark gothic theme with glowing effects
21. Player has a light radius (darkness outside = limited visibility)
22. Enemy death = particle burst (colored by enemy type)
23. HUD: HP bar (top-left), XP bar (below HP), level (next to XP), timer (top-right), weapon display (bottom)
24. Minimap in corner showing enemies as dots

CODE:
25. Single HTML file, vanilla JS, Canvas 2D
26. requestAnimationFrame game loop with delta time
27. Entity pool for enemies (reuse dead entities to avoid GC spikes)
28. Spatial grid for collision detection optimization
29. Wave manager controls spawn timing and difficulty curve