Auto save would be great. The game crashed and I lost my progress. Also, there should be a way to replay a level to earn any upgrade points lost because of a poor first score. E.G. If I only earn 2 out of 3 points on a level from a first run I should be able to replay the mission and if played perfectly, earn the third point.
Regarding rewards: If you have an Epic Creature and can win a Legendary version of it, must you first get rid of the Epic Creature? I've qualified to earn the Legendary Sasquatch but I have the Epic version of it.