Unity
Unity is a game design engine developed by Unity technologies. Originally only for MacOS it is available for Windows as well and can create games for the most modern game and VR consoles as well as for most mobile and desktop platforms.
Similar to Unreal, Unity is capable of creating real-time visuals for games (both 2D and 3D) as well as interactive simulations, film layouts, and other experiences.
Unity has less of a learning curve to get started than Unreal and it is easier to create web-based experiences with it. The backbone of Unity is C#, though users can get started without any coding experience. It is harder though to create photorealistic graphics with Unity than Unreal.
There is a robust asset store with 3D and 2D assets.
COST:
Free for students or until a company generates $100 000 annually or if released on closed console systems (PlayStation, Switch, etc.)
After this, $1800/yr/seat or higher depending on the tier