So, because I'm thinking about doing a 3d adventure game, I thought I would play something somewhat related. I picked Primordia which is a 2d point and click from a small game company called Wadjet Eye. Mainly because it looked kind of interesting and was on sale for 3 dollars. The pixels are really big when you play full screen. The puzzles mostly involve finding things to get a door open or a machine running. I had to go to a walkthrough to find some pieces of a machine and it turned out they were in plane site, just unrecognizable. The story is some robots got their power source stolen and need to find another. It's one of those post apocalyptic things where only the robots remain. Kind of a worn out plot but what isn't in games. The voice acting is surprisingly good. The art is pretty good looking for pixel art and the animations look pretty decent in a retro way.
Primordia
Hi,
I play this great game a while ago, design is very great, voice cast is awesome, story is immersive and enjoyable, puzzles are pretty well made, sometimes, as always with this kind of game, we're stuck because we miss juts one little tiny thing (same for Monkey Island, Beneath a Steel Sky which is free on dev website, and many point & click adv game). The only "issue" in Primodia is its short story which can be done in a few days or weeks of casual playing, and the story ends pretty roughly whereas other area could have been made available in the city for instance.
You may try also Machinarium which is very similar and nicely done. In fact there are a good deal of such game and their age doesn't matter at all as they will always be great to play even 10 or 20 or more years after their release.
I'll be interesting in what you'll do in the future.