If you want a time-wasting game for the Mac, consider Rail Maze. It's a free download from the Mac App Store that offers more than 100 puzzles. In fact, Rail Maze is a combination puzzle/action game, and the various levels highlight either a puzzle to solve or action to navigate. The puzzle game has you solving progressively harder obstacles as you navigate your train from one station to the next. The action levels are a railroad version of Pac Man, in that you must catch stars before a pirate train catches you.
The game is pretty fun, and it's currently one of the top downloads in the Mac App Store. It's also a great game for kids with catchy graphics and puzzles that are difficult, but not impossible. There's a few ads to deal with, b