With Unity 3D which is a game engine, you will be able to create your 2D or 3D game, starting with basic games up to triple A games if you have the motivation.
You can deploy your project within a click on several platforms such as PC, Linux, Mac, ps3, ps4, Android, iPhone, Xbox, and many others.
Perhaps development aid ?
More, you can use Unity's integrated services to accelerate your development process, optimize your project and also share your creations thanks to Unity's integrated market where you can find a lot of resources, some of them are free.
This game engine is free for non-commercial uses and commercial uses that generate less than 100 000€ in revenue per year.
In summary, Unity 3d is essentially a video game designer that instantiates objects by applying them scripts thought by the programmer that will make a game finished. Some known games are released under this engine such as Borderlands, KSP or even Rust.