I noticed that the heroes don't seem to spawn any special units, like the gold knight or super blue knight, even up to round 49.
Thank you for testing this stuff. The Javascript error is a problem with the web runtime and I don't know if I can fix that.
Round 49 - nice. You finish the game (this is the first part and the demo content) by building the world domination machine. After building the last part, the final boss comes.