Each floor of the Tower of Trials felt like a totally different world, with a completely different ecosystem.
There were all sorts of monsters and creatures within, from the basic slimes, goblins and orcs, to giant trolls, Blade wraiths, Ogres and so on.
However, for the first ten floors of the tower, these monsters were all weak monsters below Level 100 so it was relatively easy for the party to clear them.
Just that the sheer amount of monsters present made the process time-consuming, especially given that they were supposed to clear anywhere between 1 and 10 chambers on each floor.
After floor 10, there was a Boss monster they had to defeat before moving on to the next floor.
But since said Boss monster was only Level 100, it was something that the party with an average level of 270 could basically one-shot with no problems.
Then, they moved to floors 11-20, where they fought monsters that were around levels 100-200.