I really liked the game, the gameplay is satisfying, the music is good, it looks gorgeous!
There were times where i wished for more game mechanics, there are optical illusions to work around, different artstyles, etc but they were not worked with enough imo and i would have liked to see more variety in mechanics. Most levels were pretty similar in the way they had to be solved and there are very few that felt more impactful.
The game has two story lines, one in the present - your character that is looking for a machine in this world- and one in the past -about the chreators of this world. I think the voice acting was fine, the story in the present wasn't too deep but it was nice to get a phone call or message once in a while. The story in the past felt more important but the recordings you can find seemed to only record the boring moments of it. Even after ending the game and finding at least 90% of the recordings, i don't fully understand what that story line was about. I loved looking for the recorders but always felt a bit disappointed by what i heard.
I personally completed the game in about 5.5 hours and spent some extra time getting the achievemets i missed. Even with a playtime of 6.6 hours, i feel like "viewfinder" is on the more expensive side for a game. I got it in a bundle and payed a lot less (7 bucks), so i am not complaining, but i think that if you buy the game full price you might be disappointed.