DEEPGON (Tanaken)

System – MSX
Author – たなけん (Tanaken)
Publication – Micom BASIC (マイコンBASIC) June 1985
Page Scans – 1 2
Preserved By – TWE
Recommended Emulator – openMSX

Download ROM

Loading the Game –

Two versions of the game are included:
– deepgon.wav, a cassette-tape recording of the original game;
– deepgon.dsk, a floppy disk image of the translated game.

For deepgon.wav:
– After booting the machine, insert the tape image;
– Type ‘CLOAD’ and press Enter;
– After the game loads, type ‘RUN’ and press Enter to start the game.
For deepgon.dsk:
– Insert the disk image in the first slot, then boot the machine;
– The game should load and start automatically.


Game Instructions –

Move with the arrow keys.
Eat the other sea creatures by moving into them, while avoiding the falling mines;
To avoid cluttering the ground with mines, you can also eat them.


Article Translation –



The MSX Trench is a beautiful world filled with marine snow. And there lived the DEEPGON. It’s still growing and very hungry, so today, thanks to falling fish and swimming crabs, it’s still enjoying quite the feast!
Despite this, there is something it has to worry about: along with its food, mines are also falling down. Should it be too focused on its prey and accidentally bump or step into one, it’s skull will horrifically pop out. So, if any mines are coming down, it should take its attention off its prey and eat those as a last resort – you may think of it as a… “nitro-spiced” treat.

How to play

Start the game with the S key, and move DEEPGON left and right with the cursor keys. Just before the prey moves next to its mouth, move towards it as if you were biting into it. This way, the DEEPGON will automatically chow down on it.
You have a total of 3 DEEPGONs, and you have a time of 1000 to complete each stage by eating 20 prey, at which point any remaining time will be added to your score. For the NEXT GAME, your time will be shorter by 100. There are no extra DEEPGONs.


The marine snow flowing in the background makes use of character codes &H86-&H8F (&H430-&H47F in V-RAM).
If you have your MSX connected to your home’s TV through RF and the display quality makes the sprite’s shape blurry, change the ‘COLOR 15, 4, 4’ in line 120 to ‘COLOR 15, 1, 1’.

Variable Table”DEEPGON X X coordinate” “W Direction” “DG Remaining lives” “E Prey count” “Fish/Mines P Current character” “Q V-RAM address” “R Temporary character variable” “Crab (red) K, L X, Y coordinates” “G Counter” “G(30) Movement pattern” “Crab (yellow) M, N X, Y coordinates” “H Counter” “H(30) Movement pattern” “Marine snow F Current address to which to display” “Other HS High score” “S Score” “U What’s the current round?” “I, J Loop” “T Time” “A, B, C General-purpose” “A$, B$ General-purpose” Even the background processing makes this game look great. Eat the prey falling from above! Don’t eat or step on the mines. Make a mistake and your skull goes flying!! > Program annotations, in order:”100-130: Initialisation
” “140: Settings for new game
” “150: Settings for NEXT game
” “160: Draw game screen
” “180-200: Time counter/Marine snow movement
” “210-220: Draw crabs
” “230-300: Key input/DEEPGON movement
” “320-370: Fish/Mine movement
” “380-410: Crab (yellow) movement
” “420-450: Crab (red) movement
” “470-530: DEEPGON eating
” “550-590: Mine touch/Draw explosion
” “600-650: END processing
” “660-670: Marine snow movement
” “680-690: Time
” “710-790: Game display
” “800-810: Marine snow setup
” “860-930: Arrays/Character definition/Sprite character definition
” “940-950: Crab movement data
” “960-980: Seabed/Fish/Mine character data
” “990-1300: Sprite character data
” “1320-1400: Start screen display”> Footer messages:
★ Mr. Editing Chief, please publish more utility programs. Otherwise, I won’t be able to persuade my parents who think “Computers = Games”. (Niihari, Ibaraki・Hiroshi Kagami, 14 y.o.)……[Chief: Yes, understood. I will take that into consideration!]
★ Lately, it semms like the the age of the participants over at OF is lowering, but since I’m turning 18 in April, how about you leave the kids alone and go do something nice with me, Tsugumi? (Funabashi, Chiba・Junichi, 17 y.o.)……[Tsugumi: Is everyone from Chiba like this? / Editor: Afraid so.]

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