Requiring 610 for your own repair of a game cartridge would be kinda ridiculous anyway.

Besides soldering battery taps can be a pain. There can be so much thermal capacity in the taps (technically the cell, but). Combine that with an ordinary 35μm PCB, perhaps with some old school phenol board, and this result is some a newbie can be quite proud of. Heck, even if you’ve trained a bit.