Either version for Linux does not contain this evil or my system is somehow immune to this. Good for me.
Heh. You're either using a browser they don't script for, or your browser is configured to block popups.
Anyway, I guess I can't leave this topic alone. There are a number of non-evil ways to solicit donations. Unlocking additional content is one of them, but to do it in a non-evil way means the game has to be winnable, and not particularly harder to win, without the additional content. Nobody (except collectible card game and MMO players, I guess) is interested in a game where winning only means you've paid more.
Another thing that would work for a lot of players is cheap access to an internet host. Being able to telnet/ssh to a host and play without a local installation, having access to a "ladder" of high scores, knowing that you're competing against other players on the hosted machine who haven't faked their scores with savescumming etc, is worth $10 a year to a lot of players. You'd have to worry about someone setting up a competing server, but honestly? Setting up a competing server when the author is running a server for non-extortionate money would be a certifiable asshole move and I'd expect people to boycott the competitor. On the other hand if the author were charging $5 a month, then yeah, people would go to the competitor instead, and it wouldn't bother them a bit.
You could merge the donations interface with your bug/feature expansion database, prioritizing bugs that people pledge money to get fixed or feature requests that people pledge money to get implemented. If it's closed-source and you're the only person who can fix bugs or implement new features, I guess that's working for a living -- a fair business.
But if the game is open source, you're not the only person who can fix things. If there's even a hint of obstructiveness on your part, people will just fork it and community development will leave your version in the dust. The non-evil way to do it means that whoever fixes the bug or implements the feature gets the money pledged. And if that's not you, you need to do the honorable thing and forward the money to the person who actually implemented the fix. A 10% fee for maintaining the bug and pledge database and integrating the fix into the official build is reasonable, I guess, but after that you're looking at the possibility of "evil" or "obstructiveness" again. Likewise if you ignore known patches that fix things because you want the money for fixing it yourself, or any other kind of behavior that serves only to increase your profits while working to the detriment of the users.