Played by myself because I don't know anyone else crazy enough to sit through a 4-player co-op game.
I chose to play as (Crisis) Wonder Woman, Martian Manhunter, Green Lantern, and Superman. (And by the end found it quite foolish that I didn't choose Cyborg because, SPOILERS, I lost.) Their order was picked randomly.
I played with the Original Set and used every single card in both the Original Set and Crisis 1.
The normal arrangement of Impossible Mode Super-Villains and Crisis's were used (9 of each, start with Ra's Al Ghul and Arkham Breakout), but I kept Arkham Breakout permanently in play.
Obviously, Superman (S) and Martian Manhunter (MM) should focus on Super Powers and Heroes, respectively.
I tried to have Wonder Woman (WW) buy exclusively Villains, destroying every Vulnerability in her deck first.
Green Lantern (GL) I didn't have a plan for, but I though getting him Defense cards and Batmobile would be appropriate.
To start, WW bought nothing but Villains, keeping her hand at five Punches every turn and destroying all the Vulnerabilities. Psycho Pirate came out really early, basically making three players lose a turn. Other than that, nothing really bad happened and I beat Arkham Assylum as early as possible and Ra's Al Ghul a bit later.
Identity Crisis came out, flipping every Super Hero over and forcing me to get attacked by Paralax (which really wasn't too bad). The Line-Up got up to over 15 cards, but WW was able to buy Super Strength and Princess Diana of Themyscira to wipe out five Villains with cost 6+. Unfortunately, Avatar of The Rot had given out six Weaknesses which weren't able to be destroyed by WW because she was flipped over. This Crisis took me the longest to knock out, because GL would rarely have +6 Power that he could discard from his hand, which everyone needed to have at the same time. At this point, GL was become the weakest link in the team.
A few Locations came out early, and all of them were in the top half of the deck. Everyone wound up with at least one, but I let Superman get most of them.
Alternate Reality came out to destroy WW's John Constantine and replace him with The Penguin. I made sure WW bought Arkham Asylum because of this. I immediately defeated the Crisis after buying Captain Atom and destroying two of MM's cheaper Heroes. S took out Captain Cold, making his First Appearance - Attack of flipping over GL not make much of a difference.
Black Manta came out and I lost a few Equipment to the Line-Up. Collapsing Parallel Worlds was a blessing in disguise, and I managed to make a sneaky play where S played Emerald Knight to play J'ohn J'onzz to play Black Manta to gain 9 Equipment all at once, leaving WW to buy J'ohn J'onzz on her turn, making these 10 cards replace GL's nearly useless deck and discard pile (which still had 7 Starters and 3 Weaknesses). At this point, S had gotten Man of Steel and Super Strength, among many other Super Powers.
Deathstroke and Untouchable Villain came out, which didn't do much since they were defeated almost immediately, helping to get rid of S's now useless Power of the Red and the weak cards GL still had in his hand from before his deck was destroyed.
Atrocitus did next to nothing thanks to all the Defense cards I had gotten by that point and because of GL's ability, and Dimension Shift was defeated immediately thanks to GL's Batmobile.
Sinestro's high cost was once again counteracted by J'ohn J'onzz playing him to gain all the Heroes in the Line-Up, and Electromagnetic Pulse stayed around for only a bit of time before everyone had an Equipment in hand, which was harder for S and WW since they hadn't bought a single one yet.
World Domination saw Darkseid attacking each player at the start of their turn, putting some of WW's high cost Super Powers in the Line-Up, but GL could Defend S every time if S didn't already have a Defense card. Things got really stupid, as I must have tried to defeat World Domination at least a dozen times before finally having nobody have a cost 0 card on top of their deck. MM got down to so few cards that sometimes the five cards in his hand were all he had. Fortunately, Man of Steel wasn't destroyed.
And here's where I lose: Crisis Anti-Monitor loaded us up with Weaknesses, leaving WW as the weakest link at the end of the game. A Death in the Family took forever to get rid of, because Superman had destroyed all of his Defense cards trying to defeat World Domination. By the time I could finally fight Crisis Anti-Monitor, there were only two cards left in the main deck, an automatic loss, and not even one Super Hero was able to defeat him.
WHAT DID WE LEARN?
Well, I re-learned the biggest rule of Crisis mode: MAKE SURE YOU STACK THE CRISIS STACK SO THAT THE GAME ISN'T IMPOSSIBLE!!!
Identity Crisis, if it comes right after Arkham Breakout, can be a real killer, especially with 4+ players.
A Death in the Family is next to impossible with 4+ players and probably shouldn't be used.
Collapsing Parallel Worlds is still the coolest Crisis in the entire series.
J'ohn J'onzz is really, REALLY cheesy.
If there's 4+ players, make sure somebody is Cyborg, and probably don't use Martian Manhunter.
Remember that everyone has to defeat Crisis Anti-Monitor, so don't let anyone become too weak.
If you play Crisis Mode by yourself, it is way more fun to play as multiple players than to do the solo mode.
There's probably not much of a need to make a Crisis game harder if you already have 4+ players.