A computer platform is nothing without software. It was the software that made the Amiga great. The Amiga allowed programmers/developers/artists to explore a new digital frontier. That frontier has now been explored and there are exciting new places to go, with new platforms... But there are some of us who still enjoy stomping around in the old world, the Amiga's world, and it is games like this running on modern platforms that let us keep our old world alive. Without these, our old way of life would be all but forgotten.
I would say what made Amiga a pleasure to own was
1. Cutting edge custom chipset/hardware (for mid-late 80s)
2. A revolutionary Multitasking OS which didn't sap your creativity
3. The software.
ST also had some great software but the OS and hardware made it less memorable