I eventually bounced off the first Mortal Shell because it was too fucking hard, but I ended up screwing around with the Open Beta for the sequel and it got its hooks in. That's one of the best demos I've ever played for a game, and it did a mean trick where there are invisible forcefields at certain points to halt your progress. I mean, I guess they can't give the whole game away, but God Damn if that didn't inspire a purchase. Now I know exactly what's behind that shimmering curtain of force: death, death, and more death. Which I should have guessed from the jump.