If you're talking about PC software and CD/DVD games till the Xbox360, i agree with you. As for cartridges, all were imports from China and Paraguay. It was indeed impressive, with so many NES / Famicom clones around for cheaper prices. It's not like Tectoy beat just Nintendo. They actually beat Gradiente (Phantom System), Dynacom (Dynavision II, III), Dismac (Bit System), CCE (Top Game, Turbo Game), Milmar (Top System, Hi Top Game), plus imported ones like the Super Charger, Geniecom and so on. Games for them were cheaper, easily available and had a bigger importance. Still, the amazing distribution, marketing and support made Tectoy win with the Master System, and also with the Mega Drive. It's also important to remember that Tectoy was a small company and all those clones came from big and important electronics companies from that time. There's an interview with Stefano Arnhold from Tectoy, on youtube (sadly not available with English subtitles) showing how was the relationship with Sega during that era.
In fact, all the cartridges that comes from Paraguay are made in China/HK/Taiwan. I remember that Miguel Ojeda from Miky, a local company that made some arcade bootlegs (tc2000, truco clemente) and Megadrive (truco 96 and TC2000), told that the MD cartridges they sold were made in China.
Do they sell Chinese hacks or originals of games? Or is it only copies of games that were officially released?
What about if the game never got a retail release? I'd sure buy a bootleg of "Shantae: Risky's Revenge" if I ever came across one
I have no idea what Shantae: Risky's Revenge is but sure, a bootleg of an unreleased game is well worth owning. I bought a Chinese bootleg of Ninja Gaiden for the Mega Drive. I just don't really understand buying bootlegs of normal games. It was "exciting" back in the day to buy multi game carts of released games (bought one last week from Yahoo Japan) due to the very nature of them but when it comes to a single game on a cart I'm more towards the unreleased and original unlicensed games. If this shop sold such stuff I'd buy quite a few carts for sure.
well there are chinese hacks, local hacks (in the picture there's a "Futbol Argentino", seems like a Fifa 95 hack), some betas (sf2 turbo), and "original" copies.