question about Vimm's Lair website

hey, all! for context, I recently took to emulating Skate 3 on RPCS3, and I saw no other site to download from than Vimm's (https://vimm.net IIRC?).

as I downloaded it, though, I saw that my browser (Waterfox) flagged the site's connection as 'not secure,' but I still added the exception so I could download the game and wait several minutes for the download to finish, in pure excitement. the game ran fine, and so did my computer.

the thing is - I've started ruminating a lot on whether the browser's warning was right or not. i'm scared it might've given me a virus I didn't know of, so what do you all think? is my worry a result of overthinking, or should've I been less of an idiot and listened to the browser warning? thanks in advance!