B+ to B-

Most decent games fall into this category. They are fun, but don't necessarily aspire to greatness; they offer solid gameplay, stability and usually a few minor flaws that keep it just from being "okay" and just below being great. Replay value also plays a major role in a game that lands at this ranking.

C+ to C-

Games in this ranking tend to have a number of flaws but are still playable to some extent. These game don't aspire to too much, tend to stick to the traditions and conventions of their respective genres and are usually enjoyed more by fans of a specific type of game. These types of games tend to get stale in a short order.

D+ to D-

Games in this category probably started out from a great concept but missed the mark considerably. The gameplay can sometimes prove to be stale, sometimes minor design decisions that affect gameplay are questionable and the gameplay is as boring as watching paint dry.

F

You can't get any lower than an F. Games in this category are walking nightmares, usually found at the very bottom of a bargain bin. The worst of the worst, this kind of game is so nauseatingly awful that having your tooth pulled by a drunken hobo might seem like safer fun.