Maybe not actually scifi when using a stricter definition of the term, but certainly some kind of ur-scifi or proto-fantasy and an utterly important influence on many many works that came after.
Plus, I have a special affinity for this book because, well, because of this sentence here:
When I had attained the age of seventeen my parents resolved that I should become a student at the university of Ingolstadt.
As it happens, Ingolstadt, at the banks of the Danube, is my home town, where I was born and went to high school. The city of Frankenstein. We even give tourists a Frankenstein Mystery Tour during the summer months. The city also has a strong connection to the Order of Illuminati … and a minor league baseball team.
Anyway, I think Frankenstein is an important book and it’s not too long, so don’t be afraid to pick it up.