I just don't understand how to win battles in this game. The enemy units have more powerful, longer-ranged weapons. You try to close with them, and you get blasted. You try to stay away, and you can't hurt them. This isn't any fun.

Play in lower difficulty, this game is intentionally hard in the beginning to show the enemy as technologically superior, but it improves in the mid and late game.

So you could offset it by lowering the difficulty, it's much funnier to play when you slightly have the upper hand than when you are unfairly defeated.