Thanks to The Dizzy Fansite, we have learnt of three new unreleased ZX Spectrum games that were intended for release by Codemasters back in the day.
Two were complete, called Alea (created in 1987) and Hovercar Simulator (1989/91), with another called Eros (1988) which was not complete and in its early stages.
The games were created by friends José Oliveira and Ricardo Silva (under the label of Computer Weekend), who wanted to get the titles released into the British market. Their confidence in publication saw the Codemasters logo within their loading screens, even though no deals had been signed.
It is believed that the likes of Codemasters (and possibly other publishers) engaged with the coders and gave them encouragement and suggestions to improve the titles – but none would eventually make it to market.
Thanks to a Portuguese Spectrum website called Planeta Sinclair, the games were fully recovered from the developers and made available to download. The Dizzy Fansite has a great post which summarizes the findings and also includes the download links too.
With thanks to @yolkfolk_com for highlighting.