One of the best games of all time. Many of you will skim over this because you've never heard of it, because none of your friends play it or because of its sparse store page. You shouldn't.
Sacrifice offers the best mix of tactical depth and ease of learning I have ever seen in a strategy game. You play as a wizard standing down on the field where everything happens. Any units you summon are summoned directly next to you, buildings are created only by you standing next to them (for up to 10 seconds for the largest buildings), and orders are given based on what you can personally see. This makes for a much more immersive and easy-to-grasp gameplay than most other strategy games out there where you may be queuing up orders, units and buildings; might be zoomed far enough out to be disconnected from the world but not far enough out to see any useful distance.
Furthermore, the wizards you can choose from in multiplayer (you always play as Eldred in the fully-voiced campaign) are all equal. That is, everyone you might play against has access to the exact same spells and units as you. Or rather they have access to the same choices: your spell and unit lists are fully customizable offering a massive amount of variation possible. You could have ranged units that damage over time, can go invisible, can track enemies etc. Or you could pick units based on style if you prefer and do just fine: disease-ridden monsters, aloof mythical creatures, rangers, soldiers, constructs...
This customisation is in the campaign too but in a much more organic style so that you won't have to worry about choosing units based on no previous experience. Every level of the game has 5 alternatives (one for each of the gods) and each god will try to convince you the help them for each mission. You can decide who to help on a mission-by-mission basis, picking the most interesting or beneficial mission for you. You can become unwaveringly loyal to a particular god (or a certain alliance between 2 or more gods) and only server them. Or you can decide completely randomly if you like. Every mission you take increases your pool of spells or units equally, with units and spells granted by the god you choose to work for. You can also pick up heroes along the way who will be loyal to you (unless you do something completely against their nature) and will follow you in future missions until they die or you lose their trust. Every mission you choose (and don't choose) affects future levels to varying degrees. By making a god's defence stronger you protect their territory that another god or being was after and would've been able to use in future levels. Discovering something allows the god you discovered it for use that information in future battles. Capturing a village, building, character, area etc. will give the benefits of that asset to your god (whether that be a new factory, new allies, a weakness in another god or a number of other boons). This all leads to your character and the world evolving organically in a way that's not always obvious but always makes sense. By the end of your fifth mission you'll have access to a wide variety of spells and units (and perhaps a hero or two) and certain gods will have grown or diminished in power noticeably.
All of the spells are breathtaking. From the bog-standard heal and speed-up spells you begin with which create a pleasant glow/melody and a cool-looking trail effect respectively. To the more extreme spells granted later on including tornados, volcanos, earthquakes, death-incarnate and many more. In addition, most of these spells can be cast within a couple of seconds and without stopping. This allows you to run amidst your army healing, speeding up and buffing who you need, sniping an important enemy unit (or a bunch of them) and then hiding behind your own units again within a very short period of time. A lot of these spells (and some units) scare the landscape permanently too. This makes places where small skirmishes and large battles have occurred very obvious, even after 5, 10 or 60 minutes. Scorch marks, blood stains, unnatural bumps or dips in the earth, sometimes even the earth itself has gone.
The penultimate thing will mention (even though there is so much more I could say) is that the humour in this game is incredible from start-to-finish. From the gods (voiced by Brad Garrett, Kevin Michael Richardson, Castulo Guerra, Jennifer Hale and Tim Curry) to the units (every one of which with the sole exception of the manahor (an armless, mana-dispensing bunny) has a half-dozen lines if you enjoy clicking on a unit repeatedly long enough for it to yell at you to get lost) to the wizards. This game has so much personality and not in an annoying way. The humor interlaces with the rest of the game beautifully instead of being forced like in so many other games.
Lastly, this game is worth your money and time without question. Without exaggeration I have played through the campaign seven times with a vastly different playthrough and experience each time: once following each of the gods wholeheartedly, once working for all of the gods and keeping them all as friendly with me as possible for as long as possible and once attempting to keep a pair of gods powerful and friendly with each other until the end.
At £7 it's worth it easily, at half-price (as it is at the time of this review) I can't recommend it more to everyone I know. Get it, it's awesome.