No, the thorns can't be cut right now.
The purple fruit can't be reached.
The purple box can't be reached either yet.
All stripe animations are available and 4 o 5 Alt pics. The last Alt pic is not in the demo yet.
As for the demo I'm not sure if I'll update it again or just wait until I complete the game. If I update it, it will take some time since is would be a big update.