Expansion hacks: Gunbird, Sengoku Blade, and Strikers 1945
Three Psikyo shooters with a shared secret
In this edition:
Gunbird, the Saturn shmup from Psikyo has a cool test menu with a stage select, character select, sprite test, and more.
So do Sengoku Blade and Strikers 1945, two similar games from Psikyo.
I’ve made patches that let you access them. Get them from SegaXtreme: Gunbird, Sengoku Blade, Strikers 1945.
Here’s a video!
Intro
Psikyo put out a handful of shooting games for Saturn. Their credits all overlap a bit, but Gunbird and Sengoku Ace in particular share a lot of staff.
They also even share a character: Marion from Gunbird can be unlocked in Sengoku Blade:
Another thing they share is this: a hidden Test mode. This provides a stage select and a sound test in both games, and in Gunbird it also allows you to view graphical assets.
In this article I’ll describe how the test menus work. I’ll also explain how I unlocked them for the patches linked above.
Update, 2024-07-26: Strikers 1945 has a very similar debug menu. I’ve made a patch to enable it as well!
Gunbird’s test menu
Gunbird’s menu is sort of primitive, and its operation isn’t very intuitive. For example, to start playing with custom options, you have to:
Use A and B to adjust the Stage Select so that it’s something other than
-1.Do the same for at least Char1 Select.
Navigate to Stage play and press C to load the values (this will freeze the menu for a moment), then press A.
The Sprite Test and BG Check screens are similar: they won’t work until you load the values on the main screens
Demo Check plays one of the little scenes with the characters. Test Play returns you to the normal title screen.
Interestingly, you can select stages up to 17, but the two above 15 seem to be unfinished or corrupt:
Sengoku Blade and Strikers 1945
Sengoku Blade’s menu is a bit friendlier to use: left and right on the D-pad change the selections, and you don’t have to explicitly load your settings.
The names of the items pretty straightforwardly correspond to their functions except for Demo Mode - I don’t know what this does. Tell me if you do!
The one for Strikers 1945 is very similar. The Jiki items change the character for player 1 and player 2.
Technical details
The technical details of this are pretty straightforward: like many games, Gunbird and Sengoku Blade have a set of numbered “modes.” For Gunbird, the loading screen is 00, arcade mode is 01, original mode is 02, the character viewer is 04, the illustration gallery is 05, and the test menu is 08 (03, 06, and 07 are unused).
The next mode is determined by the value in the address at 060afcf0. So if we set that to 08 when the game is first starting up, we get the test menu.
0601aa06 e308 # Gunbird test modeThis changes the initial mode setting in the function at 0601a9e8, which contains the game’s primary loop.
In Sengoku Blade, the next mode is determined by the value at 06054f78. If we change its initial setting from 01 to 02, we boot into the test menu:
0601006a e302 # Sengoku Blade test modeFor Strikers 1945, the mode is stored 0604cbc2 at and the patch to set it at startup is:
060102ba e304 # Strikers 1945 test modeOutro
For previous coverage of hidden debug modes, see:
What other games should I be looking at? Send me your suggestions. Many thanks to Shadowmask for testing the patch for Gunbird.