Transistor is quite the beautiful game; from its art style to its poetic dialogue and serene music, the game excels on all fronts on providing a novel experience that feels smooth and fun to play. The combat system takes a little getting used to but once you do things start getting fun as you experiment with different combos. I feel that the 'testing room' is a great place to learn new combos because it forces you to take advantage of certain skillsets to their maximum potential. The combination of powers and upgrade slots were executed extremely well, and the natural incentive to increase the challenge (via options that simultaneously increase the amount of exp earned) is well implemented.
The tone is undeniably charming, and the characters are solid. The game leaves a lot to your imagination, but in a way that isn't too obscure or annoying. The protagonists (Red and the Transistor) are especially electric, and their chemistry is pretty much perfect.
Any complaints about the game are extremely subjective towards -my- own nitpicky tastes. One thing that did seem to annoy me was that on occasion, the combat could feel frustrating. Not in a huge fashion, but just in a way that prevented me from enjoying it to its fullest potential. I may have missed something (who knows), but for me, sprint was an essential skill because it was the only skill that was active when the transistor was on cooldown. I'm really not sure why they did this, as I imagined the game would flow a lot nicer without this restriction. Another thing is that while the art style is distinct and attractive, I wasn't really that big of a fan on the way they implemented the actual graphics during the gameplay segments. The stills were nice, but the animations/battle sprites weren't as much in my opinion. Lastly, the ending wasn't all that revolutionary for me. It pales in comparison to endings in other games like Braid, et al.
All in all Transistor is a great game, with only a few hiccups that bothered me on a personal level. Definitely a solid experience.