Extending the demos: VATLVA
Three prototype builds of VATLVA are hiding out on demo discs
In this edition we’re examining VATLVA, the car combat game.
There are three demo discs that have more-or-less complete builds of the game hiding behind the demo restrictions.
They happen to be prototype builds that differ in some interesting ways from the final version.
And they have a couple of cool debug features.
I’ve made some patches so you can explore these different versions. Get them from SegaXtreme. Here’s a video:
Background
One might translate バトルバ, the name on VATLVA’s spine card, as “Battle Car.”1 But the developers put VΛΤLVΛ on the title screen, presumably because: (1) it looks cool, and (2) it reads the same upside down as right side up.
VATLVA was never released outside of Japan, and I guess I can see why: it looks and plays more like a 16-bit game than a 32-bit game, and if you showed it to the kid up the street with a Playstation, they would laugh in Twisted Metal.
It has its fans, however, and the 6 player mode is a nice feature. Ancient and JVC Victor seem to have been proud of it, since they put it on three demo discs:
These are actually all prototype builds. The final game was finished in November, 1996. The FSS11 and SS10 demos are from September, and the Taikenban demo is from October. Playing them normally lets you see some of the game’s evolution. For example, the character select screen changes from build to build.
The demos let you choose any normal character, but restrict the number of battles you can play (one in FSS11, three in SS10 and Taikenban). So you can only see a limited amount of the game before getting the “coming soon” screen.
There are more stages and characters in the data, however - in this article I’ll describe how I managed to see and play them.
Playing more stages
The final game has logic that looks something like this heavily-simplified pseudocode:
enemy_index = 0
while enemy_index <= ENEMY_COUNT:
battle_count = 0
stage_index = 0
for battle_count in range(BATTLE_LIMIT):
do_battle()
stage_index += 1
enemy_index += 1That is, there are nested loops. The outer one advances through the different enemies; the inner one has you battle each one in different stages (the game calls these “heats.”)
The FSS11 demo restricts you by getting rid of both loops: there’s logic for a single enemy and a single battle. The SS10 and Taikenban demos preserve the outer loop, but get rid of the inner loop: you can do multiple battles, but only against one enemy.
The code from the final game isn’t very portable, so I couldn’t get fights with multiple enemies to work in the prototypes. But extending the battle limit in the inner loop lets us see additional stages in the SS10 and Taikenban demos.
There’s a hardcoded limit of 3 in both of those demos, which is easy enough to change. But the game cycles through stages for a single enemy, so we have to do some more work:
Get rid of the cycling behavior
Extend the array of enemy stages
The extra stages are in various stages of completion. Some are missing minor visual elements:
Others just use placeholder graphics:
Playing more characters
As the Japanese Internet knows, you can unlock three characters in the final game: Gell Bates, Dorry Yates, and Gato Yamada. Are they in these prototype demos?
Answer: yes! These addresses control whether they appear: set each to 03 to unlock them all:
06060a58 03 # Flash Sega Saturn Vol 11
060615cc 03 # VATLVA Taikenban
0607275c 03 # Saturn Super Vol. 10
The earlier two demos use a totally different set of sprites for Dorry Yates’s and Gato Yamada’s vehicles. The former’s is a smaller version of the latter’s.
These look to be unfinished sprites - they move unnaturally and are hard to orient. But at least Gato Yamada is way overpowered in the demos - just getting an opponent into the corner will drain their health.
Debug features
While poking around these builds, I found that VATLVA has some debug controls. Here are the addresses that enable them in each build:
06060798 01 # Flash Sega Saturn Vol 11
0606130c 01 # VATLVA Taikenban
0607249c 01 # Saturn Super Vol. 10
06060798 01 # FinalOnce they are enabled, hold L and press Y to turn on slow motion mode (and do the same to turn it back off).
On the pre-final builds, hold Y and press Z to turn on hitbox display:
Wrapping up
That’s all for VATLVA. You are free and encouraged to use the information and screenshots from this (and any other article on this site) on your favorite reference site.
For previous coverage of hidden things on demo discs, see:
What other games should I be examining? Send me suggestions!