Combat race, Marathon mode fixes

MH-Zombie

Rescue the civilians, race the clock, and raze the enemy in MH-Zombie, the world’s only helicopter arcade simulator! Three flight physics modes, three difficulty modes, and a tutorial mode provide a stepped learning curve and wider accessibility to realistic helicopter flight.

[Edit: Windows and Mac builds are up] Hey team, I got a tip on Combat Race mode prematurely awarding victory, and while debugging I discovered it also affected the Marathon mode, preventing the advanced enemy wave spawns altogether, which in turn made it impossible to win. It didn't seem to affect the Linux or Windows builds, but I don't know why... Anyway, the fox is up on all platforms. Thank you all so much for your support and issue reporting! -Joe