"Secret Agent is a shareware series of three side-scrolling platform games, developed and published by Apogee Software, released on 1 February 1992.
The first episode is available for free, while the remaining two need to be paid for. All three games have identical gameplay, and differ only in level design, some graphics and the story.
Secret Agent uses the same game engine as the earlier Crystal Caves.
The player controls the titular secret agent, known only under his codename "Agent 006½". Each game is divided into 16 levels; there is no fixed order in which to play them, but one of them is the "main fortress" which cannot be accessed until all other 15 levels have been completed.
Each level is a labyrinthine structure, seen from the side, where the player controls Agent 006½'s movements. The objective in each level is twofold; the player needs to locate a radar dish and destroy it by shooting, and find a bundle of dynamite and use it to blow up the doors to an exit elevator."
Source: Wikipedia, Secret Agent %28computer game%29 , available under the CC-BY-SA License.