I've made a game with PICO-8 with my 6-year-old watching along with me and telling me what to put into it. It was a great experience.
I do think it's very nearly almost too constrained, specifically in the code editor. But, it did it's job. A QBASIC-like interface would be appreciated.
I wish you could configure your constraints. I understand why you can't. But I just want unlimited tiles and map sizes. :)
When I was looking around the fantasy computers, I found one that was configurable. It had presets for different popular machines. I saved the link and closed the rest but when I was about to start I realised I saved the wrong one and I haven't been able to find it again. Did I just dream it? The one I started on instead was tic-80.
Found it via this list https://github.com/paladin-t/fantasy.