1. Pre-placed platforms in dungeons.
Now I understand why they are there. You'd spend half your time placing platforms yourself if they weren't there. BUT again, look at Terraria for instance. No pre-placed platforms there. But my number one reason for not liking these is the feeling that I'm not the first here. Someone else have been here, combed the place top to bottom and that really takes away from the explorative aspect. Is there no other way of doing this? Generating more real ground to make it less of a "jump around like crazy" type? Just my opinion here.
The number of these decreases as you go deeper into the dungeon, I think by the time you get to the tenth level, there are none left.
Also, I have the exact opposite feeling on these. I like the fact that they are there because it means that other people have been here and explored this cave and as I go deeper, less people have been here until I get to a point where I'm the first one. I think that is rather cool.
2. Minibosses
So far I've fought 3-4 LvL 2 bosses and I can't help but notice they've all been a pair of shadow bats. Is there no other bosses yet, or have I just been unlucky?
Those are currently the only boss that spawns underground and for good reason, the other miniboss types didn't work to well with the odd layout of the underground. If you go explore a rare commodity tower, for instance, you'll find some different minibosses.