Dear Harold,
i'm developing intensly this last month with vcs game maker, and i think to have found some bugs, i hope you can fix them as soon as possible: somethimes the emulator on the right dont react at the change in code and it is too complex to find where you are positioned in the main cartridge somethimes impossible. There are two bugs when you use a player to run the screen through left to right, it come back three times than go. Also background scroll has a bug there are some graphics artifacts every frame in the buttom of the screen. I hope to be of any help! Thank you for reding.