Another review indicates there are a series of linear combats and that's certainly true leading up the tower, which is the "dungeon." However, the tower itself provides plenty of creative and tactical opportunities to challenge tier 2 characters.
A natural inclination for tier 2 is to go investigate the top of the unfinished tower and thats where the fun can really start. I have run this twice now and both times I've had a paladin get from the ground to the top, find out what's waiting for the party, and then crater the ground below due to the sudden stop after the fall.
I do wish that the internals of the tower were better fleshed out as the first two floors several room descriptions are repeated and feel like filler time.