Hi, thanks for asking! To clarify, there are 3 levels available to everyone for free. I'm also working to make a paid version of the game with around ~15/20 levels and I've finished about 10 of those levels. I also do closed playtests of the new levels sometimes, (I've only done one so far). I'm planning to do the next one of those in May. You can sign up for the chance to be a playtester here and I'll send out game keys to the people who are selected in May. (I'm not sure I'll be able to do everyone this time, as more people have signed up than I expected), but you'll still have a really high chance of getting a key.
I'll do a few playtests throughout the end of the year as I add new levels and tweak stuff. I'm still kind of focused on improving the core gameplay at the moment so I haven't done many playtests yet, but I'll most likely do a few more in the second half of the year.
Hope that makes sense~