I've made a source repo: https://github.com/hanzou-x/Flappy5 and invited you both for write access. By basing it off the old Flappy5 you can easily see the Sp2 differences in terms of the block reward, default transaction fees, and images. I even notice a bug where one image seems to have been mis-copied.

I'll be posting a macOS client binary from this source later tonight.