HL2 is a lot more user-friendly. My gripe that it wasn't as fast paced as HL1.

It felt like they were trying to turn it into a platformer, but the first-person camera makes platformer-like jumping puzzles hard.
I found Mirror's Edge frustating for this. But half life? Most of the jumping puzzles were
really simple. Maybe it's because I'm a bunny hop god and spent most of my gaming jumping around like a grasshopper in HL1DM.

Also, the story itself wasn't that interesting to me. Guy in secret factory, monsters appear, soldiers appear and attack all the scientists too to cover it up -- very unimaginative, with no character development, interesting characters, or anything like that.
Almost like it would happen in real life. I think the story is actually amazing if you view it in a more realistic perspective. Cause if aliens were invading and shit, you wouldn't get some prologue on what's going on, you'd be confused! I really like it when a game tries to present it's story in gameplay rather than chucking cutscenes at you (that you skip anyway).
But yeah half life 2 has a more cinematic approach (without using cutscenes) in terms of characters and at least filling you in on what's going on.