You can ship GLES games on desktops no problem. And anything remotely notebook / desktop class graphics wise is so much more powerful than some Mali GPU that you can ignore "performance characteristics" for the most part and assume brute force will be fine. If your game runs on a feature phone, it will run with GLES on desktops.
What I was getting at with the performance characteristics comment - though don't ask me why I didn't act like normal people and just say this, because I've no idea - was that the game will probably look crap on a PC. That means you'll have to spend some time making it look a bit nicer, if it's to be competitive. This is all going to involve a bit more than a simple button press.
Mesa doesn't do that:
It does, every driver independently advertises GLES 3, and while it doesn't support full 4.3, every driver supports GLES 3. That post is like three years old now.