I think the Ultron boss fight is definitely something new and fun. However, the Ultron minions settings are somehow too strong to play against.
I played with three 94 level characters with full health.
The reasons I think it was too strong to against with :
- 2 waves of enemies
- 2-3 times of destroy tiles
- pop 2 critical tiles each round
- plus 1 action
I survived the first wave and was defeated by consecutive seven rounds of double critical tiles with actions.