Could you instruct me in installing several game engines to tryout? I would like to use wicked game engine, as well as flax, Lumix, and essential. I suppose if you could instruct me in one game engine the same could apply to every other one.
The only one of those available in Manjaro — albeit only via the AUR — is flax.
pamac build flax
The other ones you mention are neither in the repositories nor in the AUR — or not by those names anyway.
Also please note that while Manjaro does have limited support for gaming via steam and lutris, if you are a die-hard gamer, then you are better off sticking to the platform that those games were natively developed for.
Being based on Arch, Manjaro is a very technical distribution, albeit with a user-friendly installer and some user-friendly tools that Arch proper does not carry or does not install by default. In addition to that, GNU/Linux in and of itself was not designed for running that sort of games, and you are bound to run into trouble running non-native games on it.