I've been trying to find this game for so long. It's a Windows 95 shareware game that I've downloaded on the internet. It doesn't have the Windows 3.1 GUI style, it uses the new GUI style of Windows 95/98.
Platform(s): PC/Windows 95
Genre: Rogue-like, top-down view
Estimated year of release: shareware 1998 or earlier
Graphics/art style: Windows based like Minesweeper (not DOS protected mode), basic 2D sprite based as if they were made with MSPaint.
Notable characters: There were orc enemies. There were chests to open.
Notable gameplay mechanics: At a later level, when you open a chest, it was a trap, and the walls disappear, and all the enemies move towards you. Maybe this was a copy-protection system or a troll by the programmer, but I don't mind, I enjoyed the game and I found the trap amusing.
Other details: It was shareware, and I downloaded it on the internet. The file size was less than 1.4 MB and fit in a floppy disk.