So, I bought games from here created by Dumb Koala and have found 5 games will not load properly. I get a test pattern of vertical colored lines across the screen. Tried redownloading them and they do not work still. How do I get this fixed or a refund? I'm on a Mac, the games specifically have a Mac version. 4 games do work. and I additional I could not even download cause it was through an additional paywall.

How can I get this resolved?

You can ask for a refund by contacting support, as explained often on the forum.

Did that, but so far no response from io except for canned return email. Also contacted developer via Twitter to see if they can update the ones that failed to open properly. Bought 10 games, 4 don't work, 1 I could not download without spending extra money on Media Fire. You know when you go to buy these games there are no notifications as to what version is compatible.  Most software companies will tell you ahead of time to avoid this crap. I think this is one of the major issues. Also why must I get a Media Fire account to download some of these. So far no response from developer. Fortunately, I have  excellent standing with my CC company and can pursue a refund through them.