dotathon - entry for 2002 Minigame Compo

Public domain by Russell Marks (rus@svgalib.org)

for 48K/128K Spectrum


(NB: It won't work if a Microdrive or any other additional hardware
 which effectively moves PROG is being used. So don't do that.)


dotathon is a simple tunnel-following game, a bit like the first bonus
stage in Tempest 2000.

The aim of the game is to keep inside the tunnel of dots. :-) More
precisely, you have to keep the centre of the screen within the
squares which keep advancing towards you. Admittedly, they don't look
much like squares; only the four corners are shown.

You get 3 lives - these aren't indicated onscreen, but the edge of the
screen turns red when you lose one. Lose them all and it's game over,
and at this point you finally get to see your score. (Your score is
increased once for each square successfully passed through, with the
score increase going up each time until you lose a life.)

The controls are:

Q   up
A   down
O   left
P   right

When running the game on an emulator, be sure to either use a
fullscreen mode, or as large a window as you reasonably can. Those
single pixels can be a bit hard to see otherwise. :-)

Also, do load the game in 128 mode if you can. It has some simple but
fairly effective AY sound effects.

Known bugs:

- you can probably still get the odd bit of flicker, but I think I
  managed to fix the worst of this.

- the collision detection (so to speak) is reasonably generous, partly
  since "centre of the screen" is a fairly vague description. :-)

-Rus.

PS. The source, suitable for assembly under Unix/Linux using zmac, is
here in src.tar.gz.