It would still be rather interesting, and wouldn't make a whole lot of logical sense as to how to upgrade your ship while flying because of random things on the track. I don't think the Zombies are going to have weapons either, at least if it's based off the one from 2048, they will just ram you to take you out. I think it's just more of a brute force mode by concept, and I am basing the spawning to a certain number idea off of Call of Duty's Zombie mode. I like the simple concept of this mode, it's just the survivial of barrages from enemy ships, no confusing perks and such. Also wondering how there would be different waves if the zombies were unlimited? I would suggest unlimited waves with short breaks in between for cooldown.