Thanks for reply
Unfortunately, it's not mentioned above. Ultima/Exile series are well-known titles and have vast exploration area - while in this one, after clearance from monsters of first area (visible within window), you were moved to another one, with another castle and more difficult monsters. Also gfx were tiny but quite nice. I'm afraid it's very obscure shareware.
However, macintosh garden is very resourceful place, and I did find there many interesting titles
It convinced me to look for good emulation software.