PC Engine was arguably more of a 4th generation console than a 3rd. If anything, I'd like to see the Atari 7800 in the comparison, given that it was intended for a 1984 release window and still came out in 1986.
Even with the 6 year gap, I find it interesting how close to the NES the Game Boy was, especially since it came out before the SNES. I'm sort of reminded of the PSP and Vita, which were largely comparable to their contemporary PlayStation consoles upon release.
It's worth noting that the Game Boy's CPU, the LR35902, was based on the Z80, which the Master System used. I'm no expert, but even I know that the Z80 was a very widely used microprocessor in the 80's, and was also used in all sorts of arcade cabinets, home computers, and the Sega Genesis (along with a more powerful 16 bit microprocessor) and Game Gear. Assuming the LR35902 was not too different from the Z80, perhaps that made it cheaper and easier to develop and/or port various games to what would be largely familiar hardware.
This is interesting since the NES's Ricoh CPU was derived from the MOS Technology 6502, the other huge 8-bit CPU of the era (the 6502 was used in the Atari 2600, Apple II, Commodore 64, etc). This means, in at least this one respect, the Game Boy was more similar to the Master System than the NES. Especially when you consider that the GB is closer to the Master System's resolution, VRAM, method of Parallax scrolling, etc.
Love and tolerate.
