Gapper

A straightforward Amidar clone, Gapper adds a little twist, acknowledged
in its name. As in its predecessors, the goal here is to change the colour of
a series of lines (here in a straight grid pattern of increasing complexity)
by traversing all of them — a dotless Pac-Man or 2D Q-bert, if you will. The
player’s trail-leaving sprite, the Gapper, is ever pursued by the Seeker, a
little enemy that finds the most effective route to intercept the player,
follows it, meets up and deducts a life. In order to throw the Seeker off the
trail, the Gapper has the option of producing a temporary “gap” in its trail,
impassable by either of them until it expires.

Gapper