(Yes this is another repost but I’m moving it here) nk: Endless mode
How I think of it to work:
Enemies get harder every wave obviously, it can be enemies from any region. The difficulty will increase by level of enemies increasing and the amount of them spawning (enemy cap needed, not trying to set a computer on fire). The enemies will drop money to buy items at rest stops. Pillars are allowed to be there. Carbon will be given for each wave completion (probably 3-5 per wave completion).
Every 5-10 waves, there will be a rest stop with mo co having 4 of random items you can buy. In addition, there will be ammo and hp vending machines.
Once the player dies, no revives are allowed.
Note: I was thinking you have to complete region 5 to do endless but that’s what I think
Thank you for reading my stupidly long suggestion 
#NK Endless mode
rose merlin
My balls definitely hurt 
wanton crater
I think there's been like 3 of these suggestions lmao