Viewfinder is a first-person puzzle game that challenges your perception with a brilliant core mechanic. Essentially, you can apply a z-axis to two-dimensional images, stamping them into 3D space and letting you walk into them. Initially you only have particular pictures with which to reach the goal of each stage, but later levels give you a camera, letting you take your own shots to get through challenges. It's a wonderful concept, but one that doesn't feel fully explored in this short experience.
Photos remain as you'd expect until you superimpose them on the level; they'll be inserted from whatever perspective you stamp them, replacing anything behind them. Positioned correctly, you can use a photo's contents to reach the exit. Again, it's a fantastic mechanic that works smoothly, and it's backed up by the ability to rewind time, meaning you can redo any actions if you mess something up.
The camera takes things up a level, as you're given the responsibility to take the pictures you need to proceed, rather than being handed them. This is one of those puzzlers where solutions you come up with often feel like the "wrong" ones — finding clever ways to reach or activate the exit makes you feel like a genius.
Later complications — like cameras in set positions, and surfaces that can't be erased by your photos — ramp up the challenge nicely, but generally the game feels a little lost in itself. Once you get the camera, you don't have it in every level thereafter. One subset of levels concerns itself with optical illusions that are interesting but don't quite fit into the wider game. Many of the most memorable things you can find are completely optional. While each chapter broadly introduces new wrinkles to the gameplay, the game's structure comes across slightly muddled, and it can leave a feeling of the concept not quite fulfilling its potential.
Having said that, some of the puzzle design here is excellent, and the core idea is strong enough to easily keep you going throughout. Setting aside the narrative, which is pretty forgettable, this is a largely impressive, compelling puzzle game with a truly unique gameplay hook.