New game mode (Or difficulty?)

Eternal Limbo - Enemy health is same with normal, but ofc scales with wave level. - No challenge level, but also the player skills are deactivated. - Enemy has no buffing skills (armoured, ghost, etc) but also has no player buffing skills (Rich, loot, Wisdom, etc) - Mass/Normal levels still exists.

Maybe I'm missing something, but this seems to be a more boring version of Mazebert and, in my opinion, goes against the Mazebert style.

It's somehow a bloons TD gameplay with the endless feature. I've seen few people on discord experimenting about what they can do while removing their skill points (Mikhael is one of them AFAIK) Eternal limbo refers to the player suffering in an infinite level with the enemy stats only keeps on increasing as every round passes so yeah. You're right.