Build-a-lot 4: Power Source is not built to be overly pretty. The levels are a stationary top-down view with no ability (or need) to zoom in or pan. There are no camera controls... what you see is what you get. Further, the design is often quite iconic, using little yellow construction hats to indicate workers being dispatched, blue electrician hats to indicate technicians being dispatched and a few different types of houses and buildings that can be constructed. There are some simple animations that indicate the progress of construction while building is underway and a sort of "progress bar" effect on the houses when they're being painted, as the new color slowly sweeps across the house, but things such as houses collecting rent or needing repair are represented by a sound effect and an indicative icon displaying on top of the house. The sound effects for bad things are rather jarring and serve their purpose, getting your attention when one of your properties need repair or when a house being constructed is going to overload the power grid. There isn't any voice work; all of the "spoken" messages are simply displayed as text on the screen for you to read.

The Build-a-lot series of games put you in the shoes of a developer, buying, building, renovating and selling properties in order to meet a set of goals specific to each level. To build, you'll need materials, but you'll have to have cash to order those materials. These same materials are also needed when there is maintenance to be done at one of your properties. Periodically, your rental properties will yield cash, but not if payday rolls around and they're in disrepair... or currently being upgraded... or the power's off... or the police are resolving a dispute... or the building's on fire. There are a variety of things that will stop you from getting paid, and these are, to differing degrees, under your control.

The goals that you're trying to accomplish in Build-a-lot 4: Power Source can be straightforward, such as "own three painted houses," which requires that you buy or build three houses and have them painted... or they can require things that aren't completely obvious. For example, one level required a very high street appeal and also required that I build two power plants that both had very high negative appeal and have a large amount of rental income. I didn't originally realize it, but the very high required appeal meant that I would need to build a couple of strategically placed recreational facilities and build a work building to allow me to landscape everything, then tear down the building and put something with high rent and improve the heck out of everything in the neighborhood to max out rental income. Is there another way to pass the level? Quite possibly, but, as I said, some of the goals require you to get... creative in order to accomplish everything. Further, the set of goals you start with may not be the final list of goals for that level. From time to time, your current host will pop up in the middle of a level and add a small goal such as raising an additional $500,000 in cash. Often, this newly revealed goal would have changed your strategy quite a bit - had you known about it sooner.

In the last Build-a-lot game I played, Build-a-lot 3: Passport to Europe, I had to contend with domestic disputes in my rented properties, which required calling for the local police and/or building my own police station -and fires, which require the same sort of thing with fire trucks or my own fire station. These nuisances appear to be gone this time around.

Build-a-lot 4: Power Source has you worrying, instead, about keeping enough power running to the buildings to keep the lights on. This actually introduces a different dynamic in gameplay: the amount of power a given structure requires is based on its energy efficiency, which has no bearing on whether you own it or not. The fire and disturbance calls in Passport to Europe only affect houses you actively own, but the total power draw of the neighborhood (level) is the sum of the power draw of all of the structures in the neighborhood, regardless of who owns them.

One implication in Build-a-lot 4: Power Source is that you can buy a property, make it more energy efficient and then sell the property and you've successfully reduced the overall power draw in the neighborhood. This can be a nice way to reduce the overall power consumption and buy yourself a little breathing room, which is especially important when constructing new buildings. There is no option to build an energy efficient house in one step; you always have to build a low-efficiency building first, then add improvements to reduce the power consumption afterwards. If you're not very careful and very mindful, the initial construction will often run over your energy budget and cause everything to black out until you either improve the energy efficiency of some buildings or add new power plants to compensate.

The early levels are fairly easy and straightforward, but this is intended to prepare you for the later levels, so be mindful of what buildings allow you to do and the advantages (and disadvantages) associated with building them, so you can use them effectively in later levels.

One thing I mentioned in my review of Build-a-lot 3, but is worth reiterating in this review, is that the paydays occur at a certain frequency and you want to make sure that you don't lose money by choosing the wrong time to start upgrading your properties. Things such as repairing a house or upgrading houses during a blackout should be jumped on immediately, but if you're just upgrading your houses to increase your rent amount, you may want to wait until payday hits and then immediately start the upgrade, as some upgrades can be finished in between paydays, so you won't have to miss out on any money.

Another trick I figured out this time around is that you can control the housing market a bit, if you have enough properties. When you go to purchase a house, there are three available options: Buy the house, Offer less or Lowball. You don't actively get to set the prices, but whether or not less money will be taken is determined based on how many other properties are currently for sale. If you have several properties and want to buy more, you can put some of your houses up for sale and then Lowball the desired property. If you've put enough up for sale, you'll likely get the new house at a much cheaper price. There are, however, two downsides to this approach. First, any properties that you have up for sale don't collect rent while they're on the market. Secondly, the way the button layout changes on its own when an offer comes in on a house and you have that house selected can cause you to sell a house that you were trying to take off the market. This only happened to me twice, I think, but when you're trying to buy everything up, you don't want to actually sell one of your houses and have to wait for it to go back on the market.

Build-a-lot 4: Power Source has a relatively simply-styled interface. There is a neighborhood map section that takes up most of the screen, tabbed menus at the bottom of the screen that give you information about what can be done and the access to do those things, a small section at the top of the screen that shows your current goals and a picture of your host/client in the top right-hand corner of the screen. From time to time, your host will have something to say, which will appear in a word bubble next to him. With the exception of switching between the different tabs at the very bottom of the screen, everything fits on one screen and everything is simply tapped on to select your actions, from buying to building to improving and selling.

As simple as this interface may sound, there are some things that are a little unexpected and can trip you up. The positions of the icons you might want to click on in the menus are subject to moving when new options are added. The main occurrence of this I've noticed is that the "Accept Offer" icon will appear in the position of the "Unlist" button and push the Unlist button to the left. This happens when you have a house for sale and you're on the house's screen. As I mentioned above, this can cause you to actually sell the house when you're attempting to take it off the market. It's never a good thing when the position of buttons change in the U.I., since it can occur when someone is trying to use the button; it's far better to have all of the buttons visible and in stationary positions, but have them look different (either black and white or translucent or something similar) to help to indicate that they aren't currently available. That having been said, this didn't happen a lot, and if you're willing to wait until an offer is made on the house, you can click on Unlist immediately after the offer has been made to avoid accidentally selling the house. The cost in being careful, here, is time and, possibly, missed rent.

Overall, I found Build-a-lot 4: Power Source to be entertaining and a bit challenging, at times. If you like casual resource management games or have already played another Build-a-lot game and enjoyed it, I highly recommend Power Source. For that matter, if you're not sure, this is as good an installment as any to give it a shot.