Numbertron

Numberton is a puzzle game for one or two players, made for the early Sharp MZ home computers from Japan. The game shares some elements with Tron-like games, but the gameplay mechanics are based on numbers instead. It's easy to learn, but you'll have to plan ahead and be smart to obtain good scores.

The game may also be played as a two player battle puzzler, where the players try to kill each other by fencing each other in.