The PortableApps window becomes messed up after running games that resize desktop/dpi during gameplay. This bug has existed forever but should have been fixed long ago. It is obvious the PortableApps developers don't play games or this bug would have been resolved ages ago-either way, thank you for making a great tool.
I'm currently the only one that works on the PA.c Platform, the site, the servers, and updates most of the apps. Last year, PortableApps.com ran negative, so I was paying to keep it running. Still am. I haven't had the time to sort through handling both a screen resize and a DPI change.
Sometimes, the impossible can become possible, if you're awesome!
I've just tested Hex-a-Hop (fullscreen mode) & Descent without any (platform) issues.
N.B. try a fresh installation of the platform & some old school games.
'Life is a strategy game, where roles are already distributed'
― Neo Buddha ―