Games which are basically just 'computer games', i.e. don't have a real connection to anything real.

Games dealing with the end of the world or at least after an atomic war which has destroyed most of the world.

Actual board game conversions or 'pseudo' board games.

Based on Other Media
A conversion of a book, a movie, a TV show or even a board game. Other computer systems, game consoles or arcades don't count as other media. It doesn't matter whether this conversion has been officially licenced or not.

Games in which making money is your principal goal.

Cartoon & Comic
Reference to the visual style.

Games in which you're controlling a car, a motorcycle or any other ground-based vehicle.

Trying to teach you something, and that teaching being the main point of the game and not an accidentical by-product.

Games dealing with spys and their work.

People bashing each other's heads in. Not meant for games dealing with 'fighting' on a global scale (i.e. wars), so the fight between the first infantry division and the third cavallery doesn't belong here.

Games in which you control a flying vehicle, e.g. a plane, a helicopter or a spaceship.

Games dealing with historical situations in a more or less accurate manner. It is not enough that a game is set in the past; it has to refer to a specific historic situation or deal with real historic characters. From such a starting point, it can of course stray into non-historical directions, but not fantastic ones (aliens landing to support the American War of Independence...).

Games designed to scare the hell out of you or which incorporate a significant amount of elements typically associated with the horror genre (monsters, mad scientists,...).

Games designed to make you laugh. Not incorporating involuntary humour.

Individual Sports
Games in which deal with sports which are usually carried out by indiviuals, i.e. not in a team.

Life Simulation
Games simulating biological life.

Games dealing with transport of goods and people.

Misc. Fantasy
Games which include any 'supernatural' elements, but which don't fall under the Sword & Sorcery or Myths and Mythology themes.

Games which can be played with one or more friends (or foes). Includes all possible modes, like hotseat, parallel action, network,...

Detective fiction, whodunit and so on. 'Mystery' in the classic sense, i.e. [i]not[/i] X-Files, but Agatha Christie.

Myths and Mythology
Fantasy games closer to real myths, instead of the D&D version of myths. This means mystical fantasy, like Legend of Djel or Loom, which are much closer to the real world idea of magic (sciences that go beyond understanding, instead of guys shooting fireballs). It includes games that take heavily from middle ages myths and religion.

Games pertaining to ships, shipping etc.

Pirates as in the people whose decline is responsible for global warming.

Police & Gangsters
Games in which you play either a member of law enforcement or their opponents on the other side of the law. Not every game in which a crime is committed and a police officer makes an appearance. Games in which the player takes over the role of a private detective don't belong here (see Mystery).

Controlling a country, or at least trying to...

Advertising a product. There is actually a bit of a blurry line between this and 'based on other media'. A book conversion, for example, isn't considered a promotional game for this matter.

Games testing the player's knowlege

Science Fiction
Anything set in a possible or impossible future.

Sword & Sorcery
Not only for the pulp stories like Conan (including the barbarians in skimpy clothes that it became in the films), but also Tolkien copycats, or games like Ultima.

Team Sports
Games in which you control a whole team, e.g. football, ice hockey and such.

Text Based
Games whose main input and output is text.

Games which are still in development or which never got really finished.

Games which have got a very unique theme which is rarely (if at all) found anywhere else.

All kinds of wars, historical or fictional.

Games set in the 'old american west' - i.e. 'cowboys and indians'.