I spawned in the mushroom biome where everything was covered in crusted taint. It wasn't actually a tainted biome (thus the reason I'm reporting it here). I thought this was an alpha dev pack too since the first quest was to get wood and there were no trees around. The crusted taint began to explode since it wasn't tainted land.... at first. Flux rivers started to form and looking into the sky were gaseous clouds floating away. Thaumic slimes began to form all around and chased me down while I had no tools.
I saw a house in the distance and ran to it as the sun was setting ( I was looking at the quest book for far too long). By midnight, giant slimes were swarming the outside and little ones were jumping through the floor. There must have been a basement or cave of some kind underneath. (Revisiting a copy of the world, there was crusted taint underneath that must have exploded and created space & goo for slimes to spawn in)
The sheer amount of slimes in the area only allowed the game to process my movements once every few seconds as the lag escalated. I was forced to shut down.
Then I spawned in a new world and everything was totally fine.
Here's the seed if anyone wants to look around.
-4919163831718374166
The house doesn't always seem to spawn
