I teach a class of 20 young adults at a community college-type school (in Finland) and we start our year of game design by doing 2D stuff in Construct 3 (right after making our first board game).
It has actually become my personal go-to tool when I want to prototype an idea or get something up and running quickly. By using the available templates, you can literally have a working game ready to go in a manner of minutes. Seeing results quickly does wonders to motivation, specially with kids.
The education license is something like $25 per student per year (12 months - there's also a free trial version). This means they can also use Construct at home if they get inspired in class.
Games made with C3 work straight out of the box in basically any modern web browser, including smart phones. The app itself too runs in a browser (or optionally as a Chromium app) and uses cloud saves (OneDrive, Google Drive, etc), so you can pick up your project easily from nearly anywhere.
The Scirra forums are also quite bustling and there are tons of tutorials available. The developers themselves frequent the forum actively as well.
Tl;DR Can recommend Construct 3 for teaching game design, 5/5.
Give Construct3 a go.
It’s pretty intuitive and designed for those with little or no programming or dev experience. It’s got a free trial and the yearly license is roughly £100.
I use Construct3 - never had experience building an app before and found it increadibly intuitive.
If I recall correctly it’s about £79 for a yearks licence but there’s a free trail to let you play with it and get your head around it.