Not perfect, but it isn't wasted time.
Bad? Sometimes special bonus or items fall out of the field, so you cant get them, some people just dont work the way the say they do. It isnt really fun for a long time,
The characters, you unlock a character by complpeting one, in total there 7 characters, there all different elements and they all have different combo's and ussually they work pretty good. The missions ar very variable and some times huge nd other times really small. Most of the missions are the same missions but only out a other characters. SO you know what to do sometimes wich can be a bad thing but also a good thing if you want to come prepared to all missions.