Sorry about the bug. I think I was able to replicate it. It seems to occur if you place the balloon in the tile immediately above the squirrel. I'd love for you to try the game again. Just place the balloon further above the squirrel in the ship constructor. If it is still bugged, I'd love to have more information about it so I can fix it for the post-jam version.
Viewing post in Squirrel Space Program jam comments
Played it again and that fixes it. Great balloon physics, reminds me of bad piggies in some way. There's quite a bit of potential to this idea, but it was tedious to earn RP and its a little weird that you can't invest in a hot air balloon right away. Would be great if there was some way to steer the balloon to avoid the birds making it more of a game requiring some skill, but now its more of random chance whether you get hit by a bird and plummet to the ground.