Not to resurrect an old thread or anything, but I just received Sentinels myself (after putting it on my wish list due to this thread). Had friends over for the New Year and got to play it. We had one player who had played before, and we played two games with five players each time (with some players switching out between games). Second game, one new player said "let's go against the toughest villain" so we fought Citizen Dawn, on Mars (which turns out to be pretty brutal itself). There is a point where she becomes invulnerable until she has enough of her minions to rejoin the fight. We suffered through letting her build up her force while we did just enough damage to nearly finish off the minions, and just before that happened fire broke out doing just enough damage to kill them all... by the time we had let her build up her force long enough the second time we were sure we were done for. Lots of shifting odds back and forth and surprises. But eventually we pulled it out. Great game, highly recommended.