Interesting article, but it's strange that Indiana Jones in Wenceslas Square and the game where you have to burn books to "emit the light of progress" (!) are website conversions that bear no resemblance to a ZX Spectrum game and have made up "loading screen" graphics, whereas every other playable game[0] from the period has a screenshot from the game and plays the Spectrum code directly in browser.
[0]http://ironcurtain.svelch.com/
Edit: These seem to be proper Spectrum files for the games (for playing in an emulator):