I actually think the gameplay in 1 has held up pretty well. It's not as well-defined as 2, but it's by no means not fun, at least in my estimation. The voice acting IS goofy, but the writing is solid, so it's give and take. And while it isn't going to blow your eyeballs out, the art design is great-- and those line drawings for character portraits and on the menu are siiiiick.
and just like cj said, you will appreciate 2 so much more if you play 1 first.
I played 1 AFTER 2(because I loved 2 so much), and I thought it aged just fine.
Roger Bacon is a much better villain than Rasputin, too.
(SH's Rasputin that is. RAIDOU's Rasputin is the ish.)