Definitely the easiest game in the series ... I think if you spam the basic energy and basic tower you can beat all the levels easy enough, well at least until you take off 300+ energy and then just place whatever you feel like.
I think the story is well told, but maybe the themes are getting repeated in your games too many times ( friendship/love, being left alone, subterfuge by the central organization) . I mean I guess its hard to really demand much from a jam entry which required shoehorning with the genres and all.
I agree with Ran, its a sad thing that its so fast paced, because I don't really get the chance to enjoy looking at the animations and bad guys and stuff.
I don't really mind having the whole deck (almost) unlocked, but sadly there didn't seem to be much use or need to have so many things. I think if you were to keep on working on this, you'd need to add weaknesses and advantages to things and really make sure each thing has a use.
Anyway it was fun, colorful and overall well done.