The game engine is the horse that pulls the stacked up carriage. The most widely known and commercial base engines are the Unreal Engine and Cry Engine, but not every company releases their engine for commercial use.
The game engine is the component that combines everything together and makes it work. For lack of a better term, it’s the tool that you use to make a game function. Without it, you may have all the assets, effects, textures, and what not, but without the engine, you’re not going to get anywhere. Engines can be quite tricky as well, depending on how user-friendly they are.
The engine we use and which most people know is the Unreal engine. Its use depends on the user, and as such, some people might like it, or they might absolutely hate it, as every program and game engine has its own unique advantages and disadvantages. Furthermore, it’s only a program, a tool that you put to use, but it can crash for no particular reason, but that’s how computers are.
Each engine has a different feel and look to them. For example, you just know it’s made with Unreal Engine from the soft light and shadows it gives to the game. And the Cry Engine makes everything look real, maybe too real, which just makes the game look too polished and boring.
Nowadays engines are so developed that they can run basically everything with ridiculous amounts of polygons and texture sizes. The potential is there, but to be able to show that to a normal player depends on his machine, and that being case, not every machine can run the package, so you also have to take your consumer into consideration. So companies do have limit on polygons and texture sizes so a personal home machine can run it normally. The thing is, loading in games is the time that it takes for the computer to load the package; the entire level which you will step into. A game that kind of overdid what they accomplished was the Crysis series. When it was released, the graphics were amazing, but it took a heavy toll on personal computers because the requirements for it were quite high. But with time comes newer and better video cards, RAM, and processors. To think that 20 years ago games were nothing more than a basic 8-bit side-scroller or a really plain 3d shooter.
As technology advanced, game engines had been used not only for gaming purposes, but also saw use in the medical field as a visual-aid for studying, or in aviation for flight simulators, as well as for combat simulators.
There is also the difference between the work that a game engine must accomplish between the one used for a single player game and for a massive multiplayer game. The one for the MMO is a lot more complex.
A game engine is self-explanatory just from its name – it is the engine that runs the game, combines all of the elements in one place, and allows them function. With technology advancing rapidly, soon the possibility to play a game that looks like a high budget CG film is ever so close. But for my personal liking there will always be some beauty in crude looking elements of a game.