Blockade is from the very first issue of Chromasette (July 1981), a tape based "magnazine" by CLOAD Magazine Inc., which had been doing a similar tape magazine for the TRS-80 Model 1 and 3 machines. This first issue came out at the same time as the first issue of Rainbow magazine, and just a couple of months after the first Coco dedicated publication of any sort, Color Computer News. Dave Lagerquist, the editor and documentation writer for Chromasette, is also rather famous in the history of the TRS-80 Color Computer... it was he who first publicly nicknamed the computer "Coco".
Blockade itself is an upgraded version of a TRS-80 Model 1/3 version that had appeared in CLOAD magnazine, adding color graphics and written (mostly) in BASIC. It has a small embedded machine language routine to speed up checking for collisions. The game is the standard Snake style game for 2 players (either 2 humans or 1 computer/1 human), where the players trying pick up randomly appearing/disappearing prizes worth a variety of random point values as well as trying to trap the other player (or guiding them into one of the outside walls). Each time a player collects a prize, their tail gets longer, and they can not cross over their own body. The scoring is a little different in that there are no "lives" to worry about; you win or lose based on points or the point spread between the two players (and you can see your score go into the negatives) . Not a bad little game from this early on (the Coco had been out only about 9 months). The game can be played with 1 or 2 players, as well as either keyboard or joystick controls
Title: Blockade
Author: ??? (originally TRS-80 Model 1/3 CLOAD)
Publisher: Chromasette
Released: July 1981 (#1)
Requires: Color Computer 1,2,3, 16K RAM. Joystick(s) optional.