The game itself is solid but when it bugs it can bug bad. Not being able to evolve because apparently all 24 of my dragons are "in the dungeon" when I don't even have my tamer equipped is kinda bad.
Lemon, you need to do it on normal mode, or have an angel doll. Skill points are given by your end of level scores, you can see what you need on each one. You can get points by killing enemies (and angel doll doubles the points for a kill if the mushroom that kills an enemy has it), your lives at the end of a stage (and extra life skill points count) and by letting waves in early.
 "Arzea"){kind=icon}
 "Dead End St."){kind=icon}
 "Diamond Hollow II"){kind=icon}
 "Dragon Fortress"){kind=icon}
 "Mushroom Revolution"){kind=icon}