Per Wikipedia "Production
Lemon Interactive, the game's Polish developer, announced a competition where by the first player to find all the coins would win 10,000 dollars, but the competition was never finalised. The competition was also extended to the English-speaking world.[2] The demo version lacked some gameplay elements and only allowed players to walk through the wardrobe in their own apartment to the virtual reality lab, and access the temple VR, tomb VR and theatre VR.[3]"
Thanks, Ana. I had no idea there is a wikipedia entry for Opsys
Oh, that article is totally wrong

Lemon Interactive was not this game's developer - it was just its distributor in Poland.
The game was developed by Hypermedia from Nicosia, Cyprus - there would be totally no reason for a Polish company to develop a game in Greek and about Cyprus

Lemon Interactive did announce the contest, in Poland, like other distributors and the developer/publisher themselves had it announced in other countries.
So, the Wikipedia article's source proves that that Polish contest (for 10000 złotych, not dollars) was never finalized - but that does not mean that the 10000 USD contest for English-speaking world was never finalized either. Although I was never able to discover its results...