Filed directly under the "yes I'm old enough to remember the games this game was inspired by" category, The Sky is Falling from Ovine by Design is a retro arcade game that would have to revert to lines scratched in the sand to be any more old school. It's built around a simple mechanic that gradually gets more difficult as you play, offering up a crazy premise and a lot of gameplay mastery that only comes with practice, practice, and probably some more practice!
Rosslyn: The Templar Mystery is a captivating first person adventure game that is packed so densely with riddles, a dozen of them are staring you in the face from the very beginning and you'll barely even realize it. Taking place inside the Rosslyn Chapel (made popular by The Da Vinci Code), you have nothing but your grandfather's cryptic notes to leaf through as you wander around the chamber looking for clues. It's a challenging experience perfect for anyone who likes a good riddle!