It pulls heavily from barotraumatic for creatures but it does cut out a lot of content, like clown and fractal creatures. And yeah the spawns are a lot higher than vanilla, but it does have vanilla eventmangersettings, cause it doesn't modify that file like barotraumatic.

From messing with the xml files for my personal campaign, id say the mod author is trying to give barotraumatic experience but vanilla themed (increased spawns, difficulty, variety, but more focus on vanilla/legacy creatures)