Well, it was playable, if you like that sort of thing. I don't!
There must be some people who enjoy gargantuan setups where everybody has hundreds of units and ridiculously high resources.
There's no real point to building anything, because you've already got all sorts of stuff that you could never build anyway. A couple of those black-bodied egyptian 20,000 hit point guardians that do 2000 damage per attack, for example. More than thirty shades (the kind that enemy units ignore, and if you fly them into an enemy unit, that enemy unit simply dies). Leviathan, Scylla, Carcinos, Charon's ferries: it's a hodgepodge.
So if you like a 100% duke-it-out game, without having to waste all that time exploring, building, researching, or upgrading, and where you get to have all those powerful things from the campaign, then you'll love this scenario. Heck, it's like getting to be whatever level you want in Dungeons and Dragons!
Honestly, I have no idea - I did not have the patience to finish. I walked over the first two of my three opponents, though, and had no reason to believe that the last would be any different.
How much creativity can be involved in a slugfest? There was an attempt at a movie that was mildly interesting relating to some sort of treasure area. It showed your approach to a large and quite strange island (imagine a really tall house without roof or window and walls made of some sort of deep green goo). On the island is a lighthouse and tons of artifacts, though why you'd want them is anybody's guess, since you already have an invincible army.
At the end of the movie the map was left at a lower resolution and rotated differently than before, which was a minor irritant.
Map Design: 2
Some of this covered above, relating to the island. Otherwise, it's pretty plain. A huge island in a large lake-like body of water completely surrounded by land (on which all four players are placed).
No story. No instructions. No goals. Nothing.
I bet it was fun to design this. And for some, it might be fun to play. I would encourage the designer to take another crack at designing a scenario. Maybe add a little bit of story, some goals, and let the players explore, build, and advance a bit.