This was helpful! Spacebar (and WASD) were hooked up to a jetpack that I never finished implementing. I’m uploading a 0.1.1 version with this fixed now.
As far as missing assets in your clone, the repo uses git-lfs to manage assets. It looks like it is in the ubuntu 20 repos. If the issue was something other than LFS though, let me know. There shouldn’t be any assets missing!