I’ve posted a lot about playing these types of games as language-development activities. I’ve also written about how I’ve had students use other sites to design their own games as well.
GameBrix has a couple of levels of game design available. The first level, which uses templates already made and which users can just personalize, would be accessible to Early Intermediate English Language Learners. It’s all browser-based, like the other sites my students use. However, there are fewer writing opportunities available on GameBrix than on the other sites I have students go to for game design. It does not have a feature where players can leave comments, which the other sites have.
I think the second level of game design might be too complicated for English Language Learners. I certainly didn’t understand it, but you also have to remember that “Pong” might have been the last video game I played. However, I also have been pretty surprised with, when it comes to games, the high level of English comprehension my students seem to have. There would certainly be a lot of English language acquisition involved in order to successfully create a game in this second level.
You can design at least some games for free, but there also appears to have a subscription service available. However, I can’t quite figure out what you get with a subscription — maybe the ability to create a lot more games?