You have a working playground and have briefly released a binary. At the very least the second qualifies as a distribution, an important event when we are talking about F/OSS. Your language is therefore still proprietary.

Many current programmers think F/OSS as a norm and proprietary (released or not) as exceptionally shady. Even though some may think proprietary software is acceptable, something being F/OSS is a label with the non-trivial amount of value. Your act can be interpreted as claiming that value without actually being F/OSS, no matter what was your intention.