When I completed any of the SMBs (up to and including SM64), any Zelda (including Ocarina of Time) and Metroid Prime (never beat the first one), I definitely wanted to hold down the start button and play the game over again. I wanted to collect every item; I wanted to achieve every percentage point and I wanted to encounter and defeat every enemy. With Startropics... when I was done, I felt done. I felt like I had completed a story arc, learned the secrets of this incredible island and saved the day. The games designers had crafted a fantastic narrative, engaged and kept rapt my attention with solid gameplay, and then tied everything up in a nice bow of accomplishment.
I like to think this was attributed to the actual details of the story (which can be found here) are a means of support for the gameplay and level design. Boss fights, puzzle rooms, collectibles and scaling enemies makes me recall fondly the afternoon I spent working through this game.
Anyone with a few extra hours and would like to see what a really good short story looks like in video game form, should fire up Startropics and get with it.