This sounds great. I could imagine it takes inspiration from (or could take inspiration from) programs like Dreaming Spanish, a series of videos that are ranked at different levels of Spanish. The philosophy behind the programs is that what is most important is the active consumption of another language, like by listening and trying to understand. That actually our intuition that we need to work on generating the foreign language, by speaking or writing it, hasn't necessarily been shown by research. Instead, actively consuming another language at a level at or very slightly above your current level is perhaps the best way to become fluent at that language.

In terms of the content that you're creating, I always thought it would be very interesting to have leveled plays written in the target language. I always thought that reading how people actually speak might be more useful than reading prose.