Search free PC games by genre

It took me a certain amount of thinking to choose the main video game genres that show up in the main menu. Believe it or not, it wasn't a straightforward task. For instance, platformers and shooters are technically sub-genres of Action and MMO is not a true genre, but they are perceived as genres on their own. According to wikipedia Simulation is a broad definition that includes both management games (OpenTTD, Dwarf Fortress) and vehicle simulation games (flight simulators, etc.), but I chose to keep it simple (who calls them vehicle simulation games, anyway?). The result is, in my opinion, the most simple and user friendly way to categorize both recent and old video games.