ah yeah, that thread covers it very well.
Basically, you have a squad of 8 marines. You can play up to 6 players.
You outfit your marines from a selection of various weapons, that seem to be pretty well balanced, as well as a few extra gadgets of equipment (mines, explosives, targeting system, shield etc)
2 of your guys are sergeants who are a bit faster and tougher, and can carry an extra item. 1 guy is the captain who is the big badass.
The game is entirely turn based. Each guy has a certain number of moves, and can attack, pick up items, open or close doors etc throughout his turn.
Unlike space crusade, you don't have to finish your move in one go. So a marine can move 2 spaces, fire his autogun twice, move 3 more spaces, open a door and then fire a third shot f.x.
You can go back and forth between your guys as well.
There's quite a bit of creative warfare that can be done too:
Blast weapons can be targeted at the floor, to catch the bastard hiding behind a corner.
Mines can be set to block access to an area.
Explosives can be set, to be later shot or triggered by another explosion to create a nice big boom.
The maps are littered by things that explode, crates to search for artifacts (points), superior weapons, or the occasional booby trap.
Graphics are clear and good for a PD game. Your little marine dudes look like they face the right directions (8 looks for each guy, depending on which way he is facing, although facing doesn't have an effect in the game).
Items on the ground are easy enough to make out as well, and there's an overview map too.
Controls are pretty easy and very user friendly. You can select a marine by clicking on him in the squad overview area on the right side of the screen, or just click on him in the battle area. Simple icons with text show what options you have (move, fire, pick up etc).
Clicking on an item in the battle area shows you what it is, in case you forgot what is what. Scroll with the mouse (I'd have liked to use arrow keys to scroll too but thats hardly a big omission).
There is also a very comprehensive, easy to follow and well written help file explaining almost all the mechanics in detail. You really can't get confused here
