It's an impressive game, 100%, but I don't think the comparison is quite so straightforward. Pokemon had only 8 KB working RAM, 4 shades of colour, and the cart only had 373 KiB stored on it. But the GameBoy CPU was over double the speed of the of the BBC Micro or the Acorn Electron.

Both are really impressive games for their size; though Elite's no doubt more impressive for its time given Pokemon Red/Green released after 5 years of development to an already quite aged handheld, and ended up undergoing a full revision to patch out the bugs with Pokemon Blue version a half year later.

I think the real king is ET, a multicolor game with a layered gameworld, and detailed graphics on just a 1.2MHz CPU, 128 bytes of RAM, with less than 6KB on the cartridge. The game made a few mistakes that cost it any recognition, but it's a really impressive game given its hardware and time.