Hi! First of all, thank you for bringing that issue to my attention! I overlooked checking which files were executable for which operating systems. I downloaded the app and it seems to be working on my end, so if you'd like to try installing through the app again, it should hopefully work.
For this series I wanted to focus on more polished sprites and backgrounds, so I'm glad you liked the art! I apologize that it's short, but hopefully the later installments will make up for the length. I hope you'll keep looking forward to my future projects, and Happy New Year!