Epic Marble Race: Echo Sentry Totem vs Nebula Missile Rain | AI Physics Battle | Echo Rush Stage

English AI-generated marble race and physics simulation tournament video.
Format: 4 contenders, HP battle system, shrinking arena, and sudden-death pressure.
Featured contenders: Echo Sentry Totem, Echo Thunder Spear, Aqua Radiant Laser, Nebula Missile Rain.
Grand final matchup: Echo Sentry Totem vs Nebula Missile Rain. Champion: Echo Sentry Totem.
Rules: every fighter starts with 100 HP, collision damage accumulates, and the last survivor wins.
Keywords: marble race, physics simulation, ASMR collision sounds, HP tournament, AI battle shorts.
AI-generated content disclosure: enabled.