The whole scratch thing is extremely well put together and is easy to teach. Small chunks, fast results, forgiving environment. It gets kids thinking programmatically without even trying and for those that take to it, it is trivial to say “here are some code words, write this in code”
The only challenges are differences in ability which in a mixed class of 8-12 yo might be significant, so it would work best if you segment them into those that grasp it quickly and those that take a little longer (not necessarily age)
The hard bit with teaching kids anything in keeping them tuned in, and a segment approach can help.