The empty fields take two games with compatible "souls." The games will combine into something new and the originals will disappear. Once you have that new thing, run it to continue.
I got one together, played through it, closed the game to take a small break, and upon reopening, the game is gone. Don't know what I was supposed to get out of that game tho
Hmm...the new game is supposed to disappear when you complete it, but it leaves an object behind on the desktop that you need to complete the next task. If it doesn't, you may have encountered a bug.