Level 220 solution

Solver-verified route

1. Place Shooter 1 in lane 1.
2. Place Shooter 2 in lane 1, then wait ~39 ticks.
3. Place Shooter 3 in lane 1, then wait ~37 ticks.
4. Place Shooter 4 in lane 1, then wait ~9 ticks.
5. Relaunch Shooter 4 in lane 1, then wait ~48 ticks.
6. Place Shooter 5 in lane 1, then wait ~3 ticks.
7. Place Shooter 6 in lane 1, then wait ~28 ticks.
8. Place Shooter 7 in lane 1, then wait ~33 ticks.
9. Place Shooter 8 in lane 1, then wait ~15 ticks.

Flow mode clears this board in 51 shots with 1 relaunch.