Sixteen years after Apidya was first released, KillerGorilla and I have uncovered an entire bonus round on level 4 that has not been seen until now !
KillerGorilla from the English Amiga Board (a top Amiga forum I am a member of) had contacted me regarding the one tune on the in-built sound test menu that he couldn’t find in the game. His theory was that the tune – “Speed Of Light” – belonged to a bonus round somewhere on level 4 as it was a subtune of the main level 4 track, but he’d been unable to find the entry point to the bonus round anywhere on the level. He asked if I could look for it as I’d been “delving into” the game code while working on the previous releases of my WHDLoad patch for Apidya. So I fired up MonAm and went on a little archaeology trip…
The following are extracts from my messages to KillerGorilla during the evening of the 15th February 2008, which I think tell the story quite well:
19:06: You might however be on to something with notion of there being an undiscovered subgame in level 4. I just checked and level 4 contains a (single) jump to outside the normal game code area, looking kinda similarish to the other “start the subgame” jumps in the other levels.
22:53: Bloody ‘ell, you were right. I patched level 4 to take the Mystery Jump Of Doom and … lo … a new subgame was found ! It uses your mystery tune and the title “speed of light” suits the gameplay: you fly through a cavern and the scrolling gradually increases to ludicrous speed until you hit a wall. I have a screenshot and gameplay video to prove it exists! Now I just need to decipher the data structure the jump routine is linked from (looks like a bunch of coordinates at first glance) to see how to get to it from normal gameplay. Nice one !
01:52: There is a bug in a data table in level 4 that would prevent the “speed of light” subgame from ever starting. Two values were swapped which essentially said “move along, nothing to see here” even if you were at the right location to trigger the game.
Unfortunately, my initial 01:52 diagnosis above of the game having a bug preventing entry to the Speed Of Light round proved to be incorrect. Cut me some slack, it was made at 2am after all !
I had tracked down the original developer of Apidya, Peter Thierolf, and informed him of our discovery. After some discussion, an examination of the original source code that Peter still had and a comparison of that source code to the released binary, we realised that the game wasn’t actually bugged as I had thought. The subgame was simply very well hidden (until now) and very difficult to get into.
However, my examination of the code and data tables had revealed the entry point to the Speed Of Light round, which was previously unknown. Furthermore, a small bug was found to exist which prevents entry to the round if the player is in “flashing invulnerable” mode, but this is unlikely to affect many players.
Below are some screenshots of the newly discovered Speed Of Light bonus round taken with WinUAE:
The footage below is an example run-through of the new level. This is a recording of the first time I got the level to start properly and is (I guess) the first time it had been seen by anyone since 1992! The same footage can also be found here on YouTube.
Big thanks and multiple high-fives must surely go to the (very observant) KillerGorilla for spotting the missing tune and putting me on the scent in the first place.