It provides four hours of decent fun, up to you if it's worth the price. After those four hours it becomes rather obvious that there's way too little to do.

Game loop looks like this:
You start with a city to power.
You build a power station. In theory you have a choice from about eight types, but as long as you can affort them, they are interchangeable, they just differ by where they can be placed. Which matters very little though, since power lines across half the playing field are relatively cheap.
You place a substation and draw high voltage powerlines to it and low voltage powerline from it. There are about three types of substations, the more expensive can handle more load. Or you can just build two cheaper ones.
Every "turn" a few more city blocks are built, so you extend the powerlines to cover them. Now and then a new city is build, so you repeat the above.
As the power demand grows, some of the power lines overload and you will have to extend the powergrid around to spread to load, double the lines or just frenetically repair them every time they blow.
If you're going for ecological powersources, it makes sense to build power storage. They are huge, if you have to take your powerplant offline for a few hours, they can power a whole city.
My favourite thing is, that powerplants need maintenance once in a while and you have to take them offline for a few hours. You can postpone that and risk them being damaged, but there's never any reason to postpone it and it's the only "management" decision in the whole game.

That's it. The choices to be made are extremely limited and very inconsequential. Your goal in the campaign is to last 50 turns per map and while all maps have their special conditions, they are cosmetic at best. Research tree provides a few important bonuses (sturdier powerlines) and a couple mostly cosmetic ones. The options remain the same on every map.
There's a couple mechanics like area around powerplants and substations people don't like to live in, but for one, cities creep towards them, so you can't really control it much and for another, it doesn't really do anything. There are a few unlocks after winning a map, but they have negligible impact on the game.

The only real activity is constant expanding the the lines by a tile or two to catch up with new buildings (boring) and building more lines to avoid overload, which could be fun if there was more in it than "get to the city from another direction" or "double the number of lines". After those 4 hours I'm done with the game. At least it lasted longer than I needed to write this review :)

It took me some time to learn it and have my own style of play. It needs the user to be in constant modification of the lines of the grid and to check the power needed. This game is good choice for someone who likes the attention to detail and the general order. It needs to be careful all the time for changes. I love it! I hope for the second part or a cool update or a DLC.