Hey, first of all thanks for your comment!
We had one programmer working full-time on the project and four people who were only able to program one of the two days or less, who were helping him out.
Since our group usually publishes visual novels, we had a large amount of artists (3.5 in total, since one of them had to help with the programming) interested in helping out, which lead to this insane amount of beautiful custom art. For that same reason, we also had a composer for the background music, an SFX expert, and someone to master all the audio for us!
Most of the text bits were written by our usual editor, who jumped in when our author had to join the programming team on the last day of the jam, haha.
Sooo if I'm counting correctly, we were 13 people :)