Overall I felt that it was very challenging. Beating the last mission was very satisfying, especially since I got their base down to a little over 100hp TWICE before I finally beat them, and when I did beat them it was on the same turn that they got 100 victory points.
I'll be honest though, the only reason I found a strategy that worked was because all of their recon heros forgot their binoculars so they couldn't see my sniper that gave me vision. If they were normal recon heros that could see camo then I have no idea how I would have tackled it.
Very fun and very challenging.
