Under the Microscope: Battle Athletes

The Battle Athletes franchise has produced multiple anime series, a manga, and three video games. This article is about the 1996 Saturn game from publisher Increment P.

The game is a sports coaching simulation. Your goal is to help train the protagonist, Akari Kanzaki, for a school field day. You have six months to take her from zero to being an elite contender.

I found a surprise hiding inside this game’s data: a scrapped Virtua Gun mini-game! I made a patch to re-enable it — get it from SegaXtreme.

Here’s a video of the mini-game in action:

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The Virtua Gun mini-game

With my patch applied, you can access the mini-game by pressing Start on the title screen. It begins with the prompt PRESS “Virtua Gun” START BUTTON:

You really do need a Virtua Gun to play the game. Make sure it’s plugged into Port 2 and press its Start button to begin. Akari will begin running back and forth on the screen:

You’re meant to shoot at her sprite. If you land enough hits, you’ll be awarded points:

The game ends after 30 seconds. If you got more than 800 points, you’ll be marked as having the new high score:

That’s all there is to it!

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Technical details

It’s not possible to access the mini-game without hacking, but I suspect that the developers intended to have it hidden behind a cheat code.

The function at 060406d8 checks player 1’s input against a sequence of buttons that starts at 06048680. It’s typical cheat detection code:

      if ((p1_held_060200d6 & code_buttons_06048680[code_counter_060818e0]) != 0) {
        code_counter_060818e0 = code_counter_060818e0 + 1;
        if (code_counter_060818e0 == 12) {
          return 2;
        }

The button sequence is Up, Up, Down, Down, Right, Left, Right, Left. But that’s only eight buttons — the function is checking for 12. The array of button patterns runs into another data structure.

That would be enough to disable this mini-game entry method, but there’s another roadblock. The function mentioned above returns 0x02 if the cheat code is entered successfully, but the calling function doesn’t do anything special with that value.

I mentioned above that you really do need a light gun plugged into controller port 2 to play the mini-game. This is because the function at 06046960 checks port 2’s controller type value and compares it to the constant 0x25 — the Virtua Gun’s type.

  display_string_060485b0(s_PRESS_"Virtua_Gun"_START_BUTTON_06046920,uVar1);
  while( true ) {
    shooting_game_helper_06047338();
    if ((p2_held_0602023e == 0xf7ff) && (p2_input_type_0602023c == 0x25)) break;
    check_abcstart_06008e9c();
    if (reset_flag_060285f8 == 1) {
      reset_to_bios_0000186c();
    }
  }

You can use the gun input device with the Mednafen emulator to play the mini-game with a mouse.

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Outro

For another article about a game with hidden support for the Virtua Gun, see my writeup on Gun Frontier.

And if you like retro games, check out the latest episode of the Hidden Palace Podcast. In the latest episode, we interview Jason Scott from the Internet Archive.

Under the microscope will return next week — thanks for reading.