We recently finished our first Descent Road to Legend campaign and I thought I'd share a few thoughts on the campaign as whole.
We played the Rise of all Goblins campaign which consists of two preset missions and 3 campaign weeks which can be spent shopping in town or going on side quest. So we ended up playing 4 total quests using 2 heroes.
Let's talk about the two player mode first. Descent is built for 4 players but has rules to allow for fewer, however if you do play with less you will not have access to all of the archetypes. Certainly a warrior and a healer seem necessary for any party but without a scout you're going to struggle with traps and searches and the lack of a mage will likely mean you're going to fail a lot of willpower and knowledge tests.
Playing two player means you'll face fewer monsters but you'll also have fewer activations and be only physically able to cover two areas of the board at any given time. As compensation for the lack of actions the game grants a player in a two player party an additional action that can be used as an attack or to heal two damage. While this helps compensate for your missing companions it really doesn't replace a dedicated healer or warrior.
The Rise of all Goblins campaign is quite short, you'll unlock 3 xp worth of abilities so you won't see your hero reach its full potential over the course of the campaign and you'll only really have a single opportunity to go shopping to upgrade your starting equipment. That said I think that the campaign length is good for a tutorial and for groups with less time to commit to the game. We finished the campaign in two sittings and you could easily finish it in a single day of dedicated gaming.