I've been playing Gunpoint, an indie game on steam, that is an espionage sidescroller that involves manipulating electricity (and being sneaky, obviously) in order to complete your missions. The game is rather unique in that it doesn't give you a gun (unless you spend a shitton of money on one in the store, and honestly, it would just kill the fun of it, to me), and it actually scores you on stealth! If you're quiet, don't kill anyone, and if no one knows you're there, you get a better rank. This ties in with speed though, because your rank will suffer if you take your sweet time.
Now, getting to the electricity part- basically, at a certain mission, you'll be required to purchase a crosslink. This device will let you change how things are affected by light-switches and such- for example, you can rig a light-switch to open a locked door for you, or have it trigger an elevator for you. Eventually though, only certain things can affect other things- red can only affect red, green can only affect green, etc. So you'll get into a complicated pattern of say, having a red light-switch activate an elevator, so that when the elevator dings, it'll activate a green sound-detector, that will activate a green elevator switch that will end up activating a blue sound-detector just to open a blue door. It gets complicated and really makes you think, but it's so satisfying when you finally figure out what you have to do. There are also other gadgets you can buy that can very well change how you do the missions, as well.
There's a pretty good story behind it all, too- it starts off with you basically being hired by a woman at a company to work as a spy, but as you're on your way to see her, she gets murdered, and you're the only one on the security tapes- so simply enough, you go to get rid of the security tapes. However, there are a lot of other parties you get involved with- all revolving around this murder and the company. I haven't finished it quite yet, but it's very much grabbed my attention.
This would probably be my personal pick for GotY so far, but I'll have to wait and see what else comes out the rest of the year. If you have a spare $10, I highly recommend this.