You are Conrad B. Hart, an academic who creates a device to scan the molecular structure of organisms as part of his thesis. Rather than get his thesis published, a slap on the back and a job offer from his educational institution though, Conrad inadvertently discovers a plot by an alien race of shape-shifters who are planning to conquer the Earth. Cue a kidnapping, a brief escape from captivity and a marooning on an alien planet (with a few other familiar tropes such as lost memories and pre-recorded holocubes thrown in for good measure), and you have one rollicking sci-fi adventure on your hands. I won't go into any more detail than that, lest I spoil it for those who have yet to experience Flashback; and for everyone else I'm sure you've already played it multiple times and know all about the rest of the narrative that plays out across the game's various dystopian theatres.
As mentioned earlier, Flashback was initially released back in 1992 for the Amiga, although as documented in an interview with Retro Gamer, lead developer Paul Cuisset revealed it was initially programmed for the Mega Drive. The pseudo sequel to 1991's Another World, Flashback went one step further than Delphine Software's previous side-on adventure by introducing some pretty spectacular rotoscoped animation and clever puzzles, as well as some really intense gun play and an interesting plot. When all cut together with some amazing-for-the-time cinematic sequences, Flashback presented gamers with something that was a good few leagues ahead of previous games in the genre, such as the aforementioned Another World and Brøderbund's Prince of Persia.