LineRider is still the best. And Scratch programming is fun.

Old good stuff:

 https://www.linerider.com/

Be sure to get an orange block to start things off... one of the ones like "click green flag thing" to start. You can also just mouseclick on the top block to start... and that has a different effect, it won't reset it all, so SWIRL for instance, will keep on swirling further and further. 

https://scratch.mit.edu/projects/editor/?tutorial=home