Gates of Zendocon gets a solid 10/10 . I never got to experience this game on original hardware but I've been playing it on and off the last few days on my Evercade and have been having a blast. I'm usually not the biggest fan of Space Shooters,  Shoot 'em ups or Horizontally scrolling shooters, but this game has held my attention where others have failed. From cool looking enemies to explosions and safe spots like the awesome looking base, this game has it all. This game was released in 1989 and developed by Epyx and published by Atari Corporation in North America and Europe exclusively for the Atari Lynx. In this game you travel through different universes by going through gates that teleport you to a base where you can repair your ship and then launch into the next level/Universe. Each level has different enemies from eyeballs to dragons. While going through the levels if you take damage your ship can loose its laser cannon leaving you with only your destructor shield and Phantom bombs. There are a total of 53 levels I am currently on level 16. Supposedly there are alien's that you run into that will help you along the way I haven't run into any that I am aware of yet, but I wanted to mention it in this review. On the first level there are two gates the first one will put you on easy and the second one will put you on a harder difficulty. If you haven't checked this game out yet I would highly suggest it! Below is a Map of Zendocon.

Gates of Zendocon Map:
Each level's gates are numbered left to right, top to bottom, as the terrain scrolls from left to right.

Start
 AAAA -->BASE 1
         2/  `--.
         /       ZYBX 2
        /       1/|3 `--.
       /        / |      XRXS
      /        /  |       |
     /        /   |    1 ANEX
    /        /    |  .--' |2
   /        /    NEAT     |
  /        /      |       |
  |       |      YARR     |
  |       |       |       |
  |       |    1 EYES     |
  |       |  .--' /2     /
  |      NYXX    /      /
  |     /       /      /
  |  ZYRB      /      /
  |    |      /______/
  |  SRYX    /
  |        /
  |      BARE 2
  |      1|  `--.
  |       |      XRAY
  |      STAX        `--.
  |       |              RATT
  |       |               |
        SZZZ            NYET
            `--.    .--'
    `----------->RAZE___ 2
                1/|34  `--------ROXX
                / |                 `--.
               /  |                     NERB
              /   |    _                 |
             /    |      TERA            TREY
            /     |       |          .--'
           /      |       |    2 STAR
          /       |       |  .--' |1
          |       |      BYTE    SSSS
          |       |       |       |
          |       |    1 BETA     |
          |       |  .--' |2      |
          |      TRAX     |       |
          |       |       |       |
          |    1 ZEBA     |       |
          |  .--' |2      |       |
         TRYX    ROXY     |       |
          |       |       |       |
         STYX    NEXA 1   |       |
          |       |2 `--. |       |
         YARB     |      NEST     |
                 |       |       |
           ____  |      EBYX     |
                 |  .--'-------<-'
              1  BREX
            .---'2| 3___
        ZEST      |      
       /          |       
      /           |      STAB
     /            |       |
  ZORT            |       |
    |             |       |
    |             |    1 BOXX
    |             |  .--' |2
    |            SEBB     |
    |        .--'        TENT
    |    SNEX           /
    |     |            /
  BRAN   ZAXX         /
    `--------`--.    /
                 BROT
                  |
                 STOB
                  |
                 XTNT
                  |
                 BOTZ
                  |
                 SNAX 2
                 1|  `--.
                  |      NEAR
                  |  .--'
                 ZETA

Below are some screenshots of the game and a pdf of the manual.

 Gates of Zendocon.pdf