I've had two attempts at each side mission. Got SO close each time but WOW it's punishing.

What group are you using? I've completed them both first time with Berserker, Runemaster and Disciple.

I'm not sure but some of the Major perils seem to get you to hurry up, so get a team that isn't too defensive. All of the missions so far are about getting somewhere and then either running for the objective or killing something. One the last mission I tried to gather my party before travelling forth and got hit with two major perils for 2 then 5 damage on all party members. Thankfully I took lots of healing abilities and chugged potions but still I think the perils appear to want to rush you along so you don't gather strength.

Major perils did it for me. Chunks of health flying away. Our 3 man party got bogged down by medusas in one game and superfast +3 movement razor wings. It was grim.

Tried to rush one of the quests, and the app throw two major perils in sequence, ambushing the heroes. Pretty nasty.

Sounds like the Co-Ops. They are hard to beat. Best chance is to manipulate monster movement to best suit your party.

Our group hasn't had any issues with the mad scientist side-quest (played it about three times, I think), but that merriod side-quest is brutal.

I played my first mission very defensively & failed when the perils began slapping my party with 14 damage each!

Just completed the side quest where you have to grab the keys for the chests and the dragon turns up.

Morale was at zero, and the dwarf (using necromancer and knight) stepped up for the finishing blow just in time!!

Little gold, no experience.

Did the tutorial, and now that one. Might do one more side one before bed.

Yeesh it's tough!!

Our group hasn't had any issues with the mad scientist side-quest (played it about three times, I think), but that merriod side-quest is brutal.

It turns up a little too early in the quest order, it really shouldn't be available immediately after the tutorial quest for sure.

I haven't been able to win the Merriod quest either.

The whole Peril mechanism is a great pressure cooker. Avoid building it up by doing something at least each round: getting objective tokens, defeating monster groups, opening doors, etcetera. That seems to hold the Peril at bay, but once you are in the Major Peril zone... good luck. ;-)

I am new to Descent (but not Imperial Assault), so I'm learning as I go how best to use the Heroes and Classes.

Also, in this mini-campaign, you get 3 XP to start (or after the Tutorial Mission), and not much else after unless you buy it in the City.

I am playing solo, and ramped up to 3 Heroes which makes it a tactically rich and deep experience.

Very enjoyable, but brutal indeed.