Thanks for the comment :D We'll have to look into Tiny Wings, weren't familiar with that title!
Regarding play testing we tried to do a moderated test with someone outside the project at least once per day during the first couple of days of development. As such, we usually sat together online in the evening and invited friends, acquaintances and partners in to try it out. It wasn't really important if they were familiar with the genre, or even gamers in general, as the most important task in the beginning was to just create a core foundation that worked. Then as we came closer to the end of the jam, our focus turned more towards polish and finalization of the content we had, and couldn't justify spending the evenings doing moderated play testing. Instead we created a private version of the project and sent it out to a wider group of people to get their feedback. The value in doing it this way, was that it removed the observer bias of us as developers, meaning the experience of the players were more raw and natural and less filtered. In the same way, we couldn't help the players as much, meaning the game to a greater degree had to be able to stand on its own without our help. The dynamics between those two approaches definitely helped catching a lot of the bigger teething issues before we submitted the game. Several of the issues described by players in the comments below (Shop being too expensive, the tutorial breaking the initial momentum) comes from features that were implemented or finalized in the very late stage of the project (A few hours before the deadline) and as such we weren't able to remedy those before the jam ended.
But hopefully we can catch up to those after the jam has ended and improve them :-D