The first thing you will notice is that the format is very similar to the popular Codecademy. However, Code Avengers does go out of its way to make the format more fun and interactive for young users including a number of graphical exercises and the odd game break after you complete certain levels.
The lessons are well structured and slowly introduce the programmer to basic maths followed by variables and prompts. There are also a number of questions which are useful to check the learners understanding. I particularly liked Lesson 9 which checked how strings and variables are handled. Compared to Codecademy I found Code Avengers to have a friendlier approach and it also went over a number of points a few times meaning that it is more likely to be understood by students. The idea that they can seek help, but it will cost them points is also nice. Not only will it cause a good competitive nature between students, but it will give you an idea as a teacher which students are struggling and which are flying.
Once Code Avengers starts supporting other languages, I would certainly consider raising it to a 5* resource.
Full review can be read here.