I can see all the changes have been implemented correctly:

1. **Frame-rate independent friction** (line 1160-1161): `Math.pow(0.5, dt)` - ✓
2. **Tripled base stamina** (lines 1056, 1071): `spinSpeed: 3000` - ✓
3. **Halved spin drain** (lines 1200-1201): 3-6/sec instead of 8-15 - ✓
4. **Reduced collision damage** (lines 1259-1260): `0.02` (2%) instead of 5% - ✓
5. **Reduced wall damage** (line 1295): `8` instead of 20 - ✓

The changes look good and should result in significantly longer battles (45-90+ seconds) with smoother physics.