Desert map: a fifth map with sand dunes, three big oases, sandstone spires and rock piles, small stones, driftwood and bones. Pick it with the Biome button on the Setup screen.

Oases: every lake has many palms, bushes and small grass around it, a green ring of ground, and stones and boulders standing in the water. The ground and the grass stay dry, nothing grows in the water.

Desert haze: a thick yellow sand haze lies over the dunes and roads. It stays off the base, the shops and the oases.

Desert wildlife and sound: birds circle overhead, and red and brown crabs scuttle along the lake shores and run from you. The desert has its own music and you hear water near the lakes.

Surrender: the host has a Surrender button at the bottom of the Tab panel. It asks Yes or No, and Yes ends the run as a defeat and takes everyone back to the main menu.

Profession upgrades: a new section in the XP shop with upgrades for your profession only. The Engineer buys turret damage, fire rate and range. The Medic buys longer Health kits and stronger Health kit healing. The Heavy buys more uses for every ammo box. The Light buys Special Training, which unlocks the Shotgun, Bazooka, Flamethrower and Minigun for the rest of the run (you still buy each weapon in the Weapon shop).