I'm not entirely sure because it was long time ago and I got several cassettes along with the machine.
I do remember playing
HunchbackBut I believe most likely my first game was
Wizzard of WorWhat I do remember without a doubt that my favourite was
The Last Ninja series from that era, created by one of my father's friends (sadly uncredited entirely, this game was stolen by System3. Watch
Molem4n documentary in which Mark Cale personally admits the theft)
Cheers,
bzt
ps.: yes, I know, you can make jokes about how old I am :-)