I decapped a Special Chip 1 and took photos of the die, which is about 1/10 of an inch across. There's a little bit of damage to the top metal layer at center left, but overall I think it's good enough to work from. I'll strip the metal with acid and make another panorama.
Center left is the logo of the company that made the chip: VTI, or VLSI Technology Inc. The center of the chip has the part #, E2001. Center right has the initials HLL, maybe the designer? There are also registration marks scattered around that were used to make sure the different layers were aligned, and right of the part # are 8 pads and some circuits for testing.
I haven't spent a lot of time analyzing the chip yet, but I think +5V (pin 29) is the 5th pad from the top right, and ground (pin 16) is the bottom right pad. I think pins 10 and 24 were not connected to the die. Numbering counter-clockwise, starting at the VTI logo, everything seems to make sense except for the 3rd pad from the bottom left. It seems to connect to the substrate, so I wonder if it is the +12V pin that is normally unused. The other pins seem to line up fine, but that would put +12V out of order.
Here's a 17436x15128 pixel version (HD View on another server).
Here's a 6928x6053 pixel version (16.8 megabytes).
Here's a 1600x1398 pixel version (1.3 megabytes).
Here's the vectorized metal and contact layers (1 megabyte).
John McMaster worked on a section of the die and posted this excellent write-up.
I decapped a Special Chip 2 later. That version is used on the later games, including Splat!, Joust 2, and Mystic Marathon. The only known change is that the width/height bug was fixed (you no longer have to XOR them with $04). Here's a quick and dirty composite. Part of the chip stuck to the die; hopefully I can get that off with a little hydrochloric acid. In the upper left, you can see the modified layer IDs 10A and 40A, which are the diffusion and polysilicon layers.
Here's a 6466x5651 pixel version (14.5 megabytes).
Here's a 1600x1398 pixel version (1.2 megabytes).
Here's a 2000x1743 pixel shot of a clean SC2 die that was overheated a little during decapping (2.7 megabytes).