Like the thread title says, first off the mission was amazing. There was so much variety to the encounters; I'm really glad to see more of this caliber of level design in Spiral Knights. Also, beasts + fiends? Could have been justified a bit better story-wise in my opinion, but sure ended up being a fun combination. Speaking of the story elements, though, they were priceless!
So then what's this "HUGE problem" I have with it? The arena fight (I mean the one with the crowd of spectators) and the boss fight were much easier than the rest of the mission, and that is SO BACKWARDS.
Going into the arena, I was like whoa this is going to be epic. And then it wasn't. It introduced breakable ice, but that didn't affect the fight a whole lot and otherwise it was just a regular brawl that for some reason wasn't as difficult as the rest of the floor. Going into the boss I was like whoa this is going to be EPIC. And then it wasn't. The boss has an amazing design, from its attacks and gameplay to its appearance and especially its unique sound effects. However it just isn't a threat on its own plus so few enemies, and the mission deserves a FAR better climax.
The solution is obvious, though its implementation isn't. The solution is to tone down (to some extent) some of the encounters outside the arena and boss, while toning up (to some extent) the arena and boss. I mean, this is the solution if the difficulty of the mission isn't going to be changed.
Speaking of the difficulty, I found this to be by far the hardest danger mission of the three currently available. (I had to include the word "currently" because I didn't get to play Compound 42 before yesterday and I heard it was utterly insanely difficult in an earlier iteration.) I know people are going to ask what the hell's wrong with me and say Compound 42 is much harder than Heart of Ice even now. And to those people I say... well, I still can't fight fiends in small rooms. This wouldn't have been so much of a problem if I hadn't played the mission solo, but... well... um... I did. So there. I played Compound 42 for the first time yesterday and got through it solo without my revive cost hitting 1,000. In Heart of Ice it hit 1,000 on the first floor and I lost track of how many revives I used on the second.
Anyway... I don't have time to play the mission again at the moment, and I don't have enough experience to provide suggestions about how to tone down certain areas or how to tone up the arena and boss, so I've said all I can say about all this right now. Please fix this discrepancy, OOO; the mission is so great but this one problem left me so frustrated I just had to post about it.