The pokemon being on top of the ball will be added, as quite a few people have brought it up. I definitely need to add the option to turn the gimmicks off in the custom menu, but I was also considering just making there be 3 main gamemode: normal (has gimmicks), normal (gimmickless), and custom/sandbox mode, and making it so when you click play you then choose from those 3 options, but I'm not sure yet, lmk if that is a good idea. I also just need to get the triple/multimerge indicator, but have been kinda procrastinating it. As for different backgrounds, I'll see what I can do, and if you have any pc box backgrounds (for being in the box) or just general pokemon art to use as the full background, please let me know.
EDIT: also glad the linux download works, I didn't actually test it, and the mac version would just randomly crash, so I'm glad that seems to be only a mac issue.