so we need to make these games in unreal engine??
The games are made within Crayta which is a platform for making and publishing games. Crayta is built on the Unreal Engine so it uses the same technology with things like effects and lighting
So I have a doubt that how much ram will it use and is it easy to use
If you use it on Epic you are depended on your ram, but you can also use it on Stadia for free, which any device can use, without being RAM dependend.