This run was really saved by the "sphere of action" glitch that sometimes activates when you cross boundaries between empty space and Nav Points where enemies load in.

However, this is a really difficult glitch to replicate, and without a way to do so reliably I can't recommend Special Operations 1 for things like Marathon events. Maybe with further experimentation it could be viable, but the outright brutality of final levels makes it not very fun to try.

MOD NOTE: We discussed this and if someday there is enough interest in this game to warrant splitting into Glitched/Glitchless categories, this Zone Kill glitch would obviously be the primary motivator for that.