With the launch of TrueSteamAchievements, I was able to register and see which games I own but have hardly played on Steam. Most of them, it turns out. One of the more interesting pages is 'My Easy Achievements' which lists those achievements I've not yet won which most people who own the games in question have. This list was topped by the achievement for completing the first Act in Sonic Generations. I have absolutely no idea when I bought the game on Steam, though I won't have paid much for it.
I'm glad I did. This is a good Sonic game - particularly the 2D sections, although most of the 3D Acts are fun as well. The only real problem is that the controls feel a little imprecise at times, which I think is down to using the analogue stick (with its length of travel) over digital pads. Turning in the air to avoid spikes can take a fraction of a second too long, and occasionally I can't steer Sonic away from the walls that jut out into the 3D levels.
I played through the second Acts of Crisis City, Rooftop Run, and Planet Wisp, with a number of lives lost due to me trying to hurry through the levels. It's easy to forget that even in the original Mega Drive games you had to take the later stages somewhat slower. There's a boss battle next, but first I've got to unlock it by completing three challenges - special requirements within existing levels. What a faff.