I've also run the first part of Assault, stopping just before the croachlings. We mostly had a lot of fun so far, first time with either MCC or DCC.

I was a bit unprepared how difficult and punishing artifact checks would be for 0-level characters though. My players ended up ruining two government badges...
Which leads me to the biggest frustration with the adventure, the "blockers". I.e. skill-checks or similar you have to pass to progress the adventure. Without the government badges, my players really struggled with the grates that required DC 30(!) checks to open. We managed to have some fun with the first one, with the players having to improvise various ways of improving their odds, but the second grate was just annoying. When the players also managed to blow up the control-console for the treadmill, it felt about time to call it a night...
We might have gotten something wrong, but it seems optimistic for the adventure to presume 0-level characters will be able to succeed any artifact check, especially a combat check. Even with a group of above intelligent characters cooperate, the odds at 0-level won't be that great. This is even more frustrating when failing will likely ruin the artifact as well... One of my first house-rules will probably be that only a result of 1 will ruin an artifact.