(WARNING: LONG COMPREHENSIVE REVIEW, READ EDIT 4 FOR OVERALL SUMMARY)
This game is created by the same makers as Bastion, which is one of my favorite games ever. Upon loading, Transistor is visually appealing, and Logan Cunningham (Rucks in Bastion) makes a reappearance which is exciting. Controls are fluid, music is amazing--I'm very excited to play through this game!
EDIT 1: After playing for about an hour, I must say that I think all the expectations I have had for this game are met. Unlike Bastion, which was more of a go-get-em game, Transistor really makes you think and analyze your tactics in battle, especially with the new "time stop" system where you can plan out your actions (each move you make will cost part of your "energy bar"). There are plentiful save points, and a nice level-up system to improve your skillset. The game is mysterious so far, and I think it really fits into the mood. However, some people might dislike how the story isn't really clear, and you're just following the path without much reason until (supposedly) later on in the game when things will be made more clear.
My only qualms with the gameplay itself are the somewhat repetitive nature of the fights (although each fight calls for new tactics), and the somewhat tricky level-up system which seems a bit arbitrary. The upgrades arn't clearly defined as to what exactly they do. Overall, some parts of the game feel like I'm not sure what's going on or what I'm supposed to do to upgrade the Transistor with, but that just adds to the mysterious nature of the game at the beginning.
EDIT 2: Having come across the first "boss" now, I really think that I can speak for all people when I say--wow. The way in which the "characters" speak is amazing. The fight had me on my toes, really making me consider the best way to defeat it without losing too much health. I was blown away at how the screen colors changed and blurred as I started to lose more and more health.
EDIT 3: After tinkering for a while at an Access Point (checkpoints basically), I think I figured out exactly how the upgrades work. The Transistor has four slots which hold a primary ability. Each primary ability has two secondary "upgrade" slots. In addition, you have four passive slots. You will collect "cores" which you can slot and re-slot at any Access point. For instance, I could socket Crash() into Ability 1, with Break() as its "upgrade" to have a medium-damaging medium-range attack that mini-stuns (opposed to the regular melee-ranged attack without the Break() upgrade). Or, (normally), you could leave Crash() as Primary Ability 1 (melee-range attack) and Break() as Primary Ability 2 (Long-Ranged attack). Or, you could put one into your passive once you get more cores. There are also "Limiters" which increase the power of the enemies you face (similar to Idols in Bastion), but reward you with more EXP. Indeed, the customization is insane in this game--I can foresee myself spending quite a bit of time customizing once I obtain more cores. Play how you want to play--fighter, stealth, assassin, long-range--just customize your cores to fit your playstyle! Extremely well done, albeit a little confusing at first to figure out the customizations. Only qualm might be (if any)...there are TOO MANY choices!
EDIT 4: Finished the game, Steam says it took me ~5 hours overall, but this doesn't include the second playthrough (Recursion Mode) which I think I will be playing soon. Overall, I think this game is a worthy successor to Bastion. However, I still prefer Bastion. Why? Bastion was a bit more clear-cut and easier to process. The Calamity happened, fix it. In this game, it took until halfway through the game for me to actually realize most of the protagonist/antagonist/story arc. There were also quite a few "did not expect that" moments, which can be both seen as positive and negative overall. I personally was confused at the ending--in a way, for me, not much closure, but I accepted it. I could see it going over poorly with lots of people however. This game feels a lot darker than Bastion for sure, and I really thought that the narration in some parts was quite hefty and really tugged at my conscience. It definitely leaves you with a lot to think about and has more going on beneath the surface--you will want to play this game with a very open and sharp mind. Great to discuss as well.
Also, remember to check out all the OVC Terminals--you definitely don't want to skip those as a fair portion of the story and development relies on you reading and filling in the blanks from the information given at them (Thanks to Dragonfire973 for reminding me!). Also, when you have time, make sure you socket all the functions into every slot (Primary/Secondary/Passive) and read up on all the information unlocked.
Amazing Artwork, Beautiful Soundtrack, Superb Narration. I expected nothing less.
Lots of customization for how you want to play the game.
Story-arc similar to Bastion, so this story will feel somewhat similar.
Somewhat repetitive battles, but interesting nonetheless.
Often confused as to what really was going on story-wise (not much explanation of what was going on), but this could be intended.
Not much closure for the ending, but definitely lots to think about. Really made me think about the whole story after the credits had rolled.
A very nice game overall. The aesthetics of the game are unmatched. However, some people might feel like the game is a bit confusing to wrap your head around. I preferred Bastion's ending to Transistor's, because Bastion was more clear and provided some closure. Transistor left me wondering what really happened and left me with too many unanswered questions. However, it did leave me with a lot to think about, and I want to go through the game again to see if I pick up anything I missed the first time through.
If you have any doubts on buying this game, your doubts should be dispelled--this game is worthy of your $20; a beautiful second game released by Supergiant Games.