Music was really well selected. After figuring out what I actually had to do, I made it to level 4 and then Invagast walked off the map and wasn't able to recover. The controls are difficult, until you realize that you can drag the map around with right click, then that works quite well. But the pathfinding of your units needs work, sometimes they just don't move when they can't go a direct way. Or they walk around obstacles the longer route and through enemy fire. Projectile animations would definitely have helped to see the ranged fighters' range better. Another tip for the opening...the font is really hard to read and it's a lot of small text, with some spelling errors. If you wanna keep that font, maybe make it larger and tell the story in a couple short sentences.
But it overall it was a good effort. Making a game with controlling multiple units is not an easy thing to do, so hats off.