Is it possible to remove free downloads and have a bar set for people to play for a donation.
At that point, it’s not really a donation, but people trading money to play the game, so it’s a sale.
I just want to avoid causing some problems with using for sale on a game that’s not fully complete on purchase.
There are many projects that are paid, and have versions available in alpha or beta. Putting your project on sale will not cause any issues with the site. You just need to make sure it is very clearly indicated in your project page, that whoever is spending money on it, will get an experience that is still being worked on, to manage expectations.
Also in your project’s settings make sure to mark it as “In Development”.
Hope this helps :)