I'm not a solo player but I love to discover what they do to make it fun.
1) rules are easy if you know poker. If you don't, no worries, everything is in front of you with reminders.
2) easy to setup. I was surprised. You create the encounter deck, shuffle the deck of cards and you are ready to play
3) good variety of enemies. Each time you kill them, they give you something to help.
4) it doesn't take too much space.
A good surprise. I like it