We played the actual game yesterday on Warhammer day.
It went pretty well. The game went how I envisioned the art from the Rogue Trader book playing out. A massive horde of aliens were approaching these cut-off and out numbered marines.
These guys didn't all cluster up, back-to-back as the art, but they did die a couple of marines a turn until they were all wiped out on turn five.
After killing piles and piles of Orks, of course.
They killed the dread, the battlewagon, a unit of Meganobz, a unit of lootas, a unit of burnaboys, a unit of deff koptas and three units of regular ork boys.
The Stompa killed a marine in close combat. The others died from slow attrition after being shot or assaulted by many, many orks.
Here was the last marine to die standing in the midst of a horde of greenskins.

This was the start of the game.

The marines scattered right away. With the ordinance coming down from the Stompa and the Shok Attack gun, they didn't want to be too close to each other.

The Orks stomp up with the Deff Dread, confident that it will be able to inflict some damage, while more lootas come on from the Fist's flank after the first unit of them was wiped out.

The first marine to engage the enemy at close quarters is quickly surrounded.

He manages to extricate himself from that situation and only has to face the dread.

He wards off the attacks from the hulking machine before plunging his combat knife through an opening in the machine's armour and right into the Ork piloting it.
The marines continue to fall back with the menacing xenos hot on their trail.

Sergeant Cabrera moves to rescue one of the battle brothers from the greenskin tide. Between them they slaughter many of the foul aliens and set the rest to flight.

Meanwhile the Orks bring their Deff Koptas around to cut off any retreat.

After dealing with the Orks, the Astartes turn on the vehicle that brought them to the battlefield. They quickly barge aboard and slaughter all the crew, leaving some krak grenades behind to render the machine inoperable.
Eventually even those heroes succumb to their injuries and only one battle brother is left standing.

Surrounded by the screeching green Gretchin dragging at his armour the marine makes a final standing, selling his life dearly, but still losing it.