COMPETITION ENTRY #32: SNAIL MAZE
"Salvador" is Spanish for "Saviour", and I wonder if Señor Camacho is trying to be the saviour of my crusade to get a double-figure number of entries for the ZX81 in this year's CSSCGC. It's his third entry for the Spectrum's 40-year-old predecessor, to add to his one entry for the ZX80, and once again it's written in C using Z88DK and compiled into ZX81-readable machine code. Snail Maze is a demake of a game that was built into the Sega Master System's BIOS before it was kicked out in favour of Alex Kidd in Miracle World, and as it's previously been converted to run on a Texas Instruments T1-84 Plus CE graphical calculator, the ZX81 shouldn't have too much trouble handling it.
Obviously this version is shorn of the colour, graphics and jaunty in-game tune of the 1986 original, and requires the walls to be the same thickness as the empty spaces, but otherwise it retains the essence of the gameplay. It's introduced by a title screen, which tells you all you need to know, i.e. the controls - the standard Q/A/O/P, nothing fancy - and your objective, which is to move your snail (an asterisk) to the goal (a capital G), hence there's no need for any documentation. I think there could have been a better snail character than the asterisk; the @ character of the Spectrum would have been ideal, but a 9 would still have been an improvement as it resembles a snail more than an asterisk ever could. Minor gripes aside, press any key to start, and you'll be given your first maze. As ever, Salvador has provided a link to the original C code; my knowledge is limited, which is why I can't explain how these void printMicroPalote procedures generate the mazes. All I do know is, the mazes will be the same every time - there are five of them, and the fourth involves no decision-making, it's just a sprint - if such a word is ever appropriate to be used around snails - to the finish, and it's a callback to the original game's twelfth and final stage, which you can see via World of Longplays - though even this version isn't what you'd call long!
The game is easy - really easy. I beat it on my first attempt, despite having to take screenshots for this review at the same time. It is only possible to fail by running out of time, which you won't unless you're catastrophically bad at maze-solving (and that's only on four of the five stages). "Time" at the top of the screen may look tight, but each time unit is just over two seconds, and the asterisk-snail moves rather faster than a real one ever could. If you don't make any mistakes, you can blitz through the entire game in a shade over two minutes, 20 seconds of which will be spent waiting for the mazes to be drawn (i.e. four seconds each). You'll be rewarded by an animated end screen which is a reference to Mr Palo T., which us mere mortals outside Spain would never have known. I won't spoil it - load the game and see it for yourself.
As an extra note, Salvador says that one of the reasons for making this game was to test a technique he'd seen in a 1982 issue of El Mundo del ZX81, which had then been expanded upon and translated for Z88DK, whereby Spectrum BASIC's SCREEN$ function can be simulated on the ZX81 by PEEKing the display file, which stores whole characters - and it is this technique which determines if the snail has reached the goal.
Overall, it's another entry which I could never award more than two masks for attainment, mainly because you'll see everything it has to offer in five minutes maximum, and it takes more determination to fail than to succeed (there's some Crap Game credibility if ever I saw it!) I would rate it at three Ricks for effort, as I would expect Salvador to be more fluent in Z88DK than he admits to being before. I'll allow it for the Green Challenge as it's a definite case of a demake, although I really intended that to be shifting from one Sinclair (or Sinclair-related) format to another. It doesn't really pass the type-in test, though - it fills almost the entire 16K of the expanded ZX81's memory - though, as Salvador admits, some of that is the end animation - and would be thoroughly impractical to enter with the standard hex loader and an initial REM statement so long that even the finest wall-builders in China would have to think twice.
It is encouraging to see the Spectrum's predecessors given some attention in this year's competition after a very shaky start. Keep them coming, Salvador - and everyone else, as well.