It depends on the game and how you've programmed it. I mean, AppGameKit is akin to DBPro, the command syntax is very similar, there are some formatting differences as well - arrays use square brackets for example. If your taking a sprite based DBPro game and transferring it into AppGameKit, then it wouldn't take long at all.
One annoying thing I discovered yesterday though, AppGameKit doesn't have byte access when dealing with files! - so if you have a complex level file format for example, you might have to change that, like use integers instead of bytes. Little things like that crop up, but really there is no need to procrastinate, better to just get stuck in and deal with issues as they come.
Health, Ammo, and bacon and eggs!