In the last level those green robot things are too hard to beat, i throw 3 grenades at them, then shoot them in the head with an upgraded plazma thingy and they're still alive... They can all see through walls and predict where your going to move next so theres no way to sneak up on them... Iv'e been trying to beat this level for ever but cant get past the first robot. Either i suck or that robot needs to have less health.