I haven't checked the format of the RUBE json files but it is certainly possible to parse json output from Spine in Tier 1. I'm already doing it.
Reading a text file that has a set format? Of course that's possible in Tier 1...
I'll take a look at some point but I haven't read anything in the Wikipedia page on json that would make me think this wasn't possible yet.
Edit: Looking at the
json output from RUBE there are a couple of Box2D features missing from AppGameKit such as the chain object but that could be faked using a string of thin rectangular shapes. Other than that the json format itself is pretty easy to read and therefore to parse manually. Pretty quick too if my json parser is anything to go by.
If GetDayOfWeek()=5 then initParty()