Ah, yes. Dendy. That pirated NES clone. Fun memories. It all started with that little console plugged into an old tv.
I had a really large collection of cartridges. I completed most of these.
In no particular order. Duck Hunt, Mario Bros, Super Mario Bros (made it to world 7 without warp tubes), Super Mario Bros 2 (iirc it was that game what was all a dream of some sort with playable Toad and Peach) Contra, Super Contra, Ninja Gaiden 1, 2, 3, Castlevania II Simon's Quest (considering dubious hints and my lack of understanding english language at the time i somehow managed to beat it. Easiest Dracula in the series.), Top Gun, Duck Tales 2, 3, Blaster Master, TMNT 1, 2, 3, Adventure Island 1, 2, 3, 4, Magical Doropie (it's like a Megaman, but you're playing as a witch who can summon a broom and has all 6 abilities unlocked from the start), Chip & Dale 1, 2, Back to the Future 2, 3, Tom & Jerry, Lion King (i never finished that ostrich race), Double Dragon 1, 2, 3, Battletoads 1, 2, Battletoads & Double Dragon, Adventures of Rad Gravity, Robin Hood, Road Rush, Tiger Heli, 1942 (or was it 1943 not sure), Legend of Crystal Palace and other games i can't remember at the moment.