Big improvement to the original, both in terms of new content and balance changes. Heroes are playable, there is a more proper story campaign which I adore and there is the whole new aspect of space combat, including the infiltration of the enemy ship.
But it has its rough edges, especially with the AI, and there are some aspects of 1 I prefer and the missing maps from 1 are also tragic.
Still, this will forever be near and dear to my heart and guarantees hours of blast every once in a while.