While there was no actual tickling, best of my knowledge, in the game, one of the ghouls in the UnderWhere section does mention it. When you talk to it, it tells you someone fell into the River Twigz when their game ended and that they suspected that the ghosts in the river were tickle torturing them. Kinda surprised me, but what surprised me more was the fact that the ghosts in the river were just hands with a segmented, snakelike body. A potential tickle opportunity and it gets wasted......