It's amazing the impact that a little safety-management can have on something as simple as a card matching game! This is a really good idea. As someone who's not very good at these games, I'm grateful that it was merciful enough for someone like me to get through it! In a future version maybe it would be cool to make the ghosts come in more quickly as you get more matches, so the tension gets higher as you go (instead of lower, like in normal card matching). A very original idea! Nicely done!