It is indeed well made, and I love how they shift and scroll backgrounds so smoothly on the Intellivision. BTW, ha ha, the death sfx sounds lots like the one in Coleco's DK for Intellivision.
The sound effects were painstakingly replicated one by one, second by second from the MSX version (possibly at a slower speed than NTSC MSX would run, not entirely sure which speed is original). I learned a lot about the ON FRAME type sound effect engine which I've had great use of later.
It is entirely possible that my lack of skill affected how much I liked it! 🤣 It does control well though, so personal preferences aside it's certainly not a bad game. 🙂