TRON is one of the oldest computer games ever and a very popular one. Both probably due to its simplicity to implement and complexity to master. It's also a lot of fun when played against real players.
It is considered action game, but could be classified as logical as well. It requires visual thinking and fast reactions from players and a whole great deal more from the developers in order to make decent computer opponent. The task of creating the artificial intelligence for the computer player used to be a common topic in many MSc thesis's from the recent past...well the truth is in the Palm version we have not done very good job in it and the excuse is the device capabilities are really limited before the new over 100 MHz processors come around...until then, the game will be best at its best - against other players.
TRON was named after the movie "TRON", a major wide picture from the early 80s. If you still haven't seen that movie, try and get it. It had reportedly created a small sub-culture back at the time.