Corinth River is the first level of the game, and is, predictably, quite simple. You will learn the controls, try out a few different weapons, and complete other tutorial-like actions. This mission probably won't cause much trouble on Elite provided you follow the general strategies.

As for the level itself, you will walk around on a space ship before crash landing on the surface of the planet. You will fight across a beach, then through a warehouse, and a few other indoor locations. Eventually, you will be out in the open in a massive battle between the ISA and Higs. After killing a few machine gunners on a high up walkway, you will drop down to the ground and take control of an ISA tank for the rest of the mission.