Sonic Adventure 2: Battle - Final Chase - m5 - All rings (653/653)

Almost two years ago, I recorded Cosmic Wall all-rings (well, all rings on Dreamcast, because that was what I had). It was tough, but I completed it in the nick of time: not three minutes after I finished recording the material for that video, my Dreamcast broke, victim of a bad disc motor.

Some months later, I tracked down the internal files that made the game tick, mainly the object definition files. Deciphering them without a working system and game to check with was tough, but out of all people, go figure that I knew the game well enough to undertake such a task from memory. So now I had a deeper understanding of the game, but couldn't do anything with it.

Flash forward to October 2010. I picked up a GameCube for my birthday (sticking to last-gen consoles is nice and cheap and you should try it some time). So almost 9 years after its launch, I finally got my hands on Sonic Adventure 2: Battle, despite already being a leading authority on the game by proxy from what I knew of the DC version. I explored it to see what was different, but ultimately I didn't find anything new that merited a video. So the game just sat in its case for a while.

Earlier this year, I got hold of the SA2B object files to go along with the SA2 set, so now I could exhaustively scan for differences. Most of it was expected, and/or decorations, but there were a few surprises.

SA2B wasn't just a verbatim port of SA2. Among the changes, they sought to take advantage of more powerful hardware by adding detail in many levels. Inevitably, there were ideas that didn't pan out and had to be removed. Normally this was resolved by deletion, but in a few notable cases they "blanked out" such objects.

Object entries are 32 bytes long. If all the bytes are zero-valued, it still has semantic meaning: "Place object #0 (a single ring) at the coordinates (0,0,0)." And SA2B has two spectacular examples of this.

You may already know Metal Harbor: in hard mode only, you can see a ring floating below the start, and touching it awards 75 rings. That's the result of the game dutifully loading set0010_hd_s.bin, which has a 2400-byte stretch of nothing but zeroes shortly before the end. The origin is fairly easy to reach in that level, and you can't do anything with the rings except die, so that's about as far as the mystery can unfold there.

But there's one more level that was the victim of a mass blanking, this one far more obscure (unless and until this video itself shapes public perception). Like Metal Harbor, Final Chase also has a GC-only, m5-only ring stash. This time, it's even bigger: 4192 null bytes, for 131 rings. And this time, the stage is different too...

(0,0,0) is a short distance above and behind the starting point. And by happy accident, the starting rail keeps curving back...directly to the origin, beyond which point the rail keeps snaking further up, but it dematerializes as soon as that X-coordinate goes positive. It's a tough camera to fight, but you can get there and see 131 rings floating there as one, just beneath the highest point the rail will take you before throwing you off the edge of the world. And thanks to the light dash, you can grab them and land back on the rail to continue on your merry way.

A word of caution. That glut of rings makes for the one and only chance in the entire game to demonstrate an extremely obscure technical limitation: Characters can only process collisions with 128 objects in a single frame, and the light dash sometimes takes you through the rings in just one frame before you land on the rail. In this case the remaining 3 rings are left behind, and you'll have to go back up for the leftovers if you want all the rings. Thankfully that didn't happen here.

Getting the rings right away will put you on a good start for 623/623 rings (and getting a shield from the first checkpoint is nice), but is that the best you can do? Of course not! Taking advantage of son1cgu1tar's deceptively difficult backtrack to the first sloped road, I brought two checkpoints into the fold and set out on a mission: as tight as SA2 ring stats were, I had the chance to demolish a record there by 125. Suffice it to say, this is the last time we'll ever see such an improvement to a ring record in this game.

Special thanks to "brianpso", who sent me a PM last week asking about weird stuff in the game. I was going to mention the Final Chase rings, but first I wanted to see just what the situation regarding them was, and once I found out that they were in fact reachable, I had to put my response on hold. There was other business to attend to.

For the first time in a long time, I saw the chance for a stat that was so jaw-dropping that it would justify my return.

It's nice to be back, isn't it?