I was a little kid when I was playing it so I don't remember that much.
1. Most likely point-and-click
2. You were controlling a small ghost wearing a black robe and a lantern
3. It took place on some kind of amusement park and a castle.
4. You needed to help other ghosts to get "currency"
5. This "currency" was usable during a boss encounter (a big clown, minecart ride)
6. Your healt points meter was a main caracter face that changed emotions
7. Definately a kids game.
Pic not related. Help me anons, nostalgia struck me like hell.
oh and also the cover of the box was the main character ghost holding a lantern