Here are a few more ideas that could be quite challenging
Or maybe not!
Why not try...
Adjust the scoring so that if you miss the dinosaur, you will lose a point
Hint; Put another sprite on the base of each hole.
copy score code from dinosaur but then adjust change score to negative value.
Make one then duplicate.
Introduce another, harder level
Instead of ending the game at 50 points you could broadcast a message to change backdrophide old sprites and show new ones.
Remember you need to include coding to reset everything when the game restarts with green flag.