If it was an older, simpler game (perhaps 2D) that didn't have an engine attached, or was in Java or C#, there might be some hope for disassembly being helpful, but with Unreal Engine as part of that exe the code is impossible to meaningfully reconstruct, even if you dedicated the rest of your life to it. Decompiling can be useful for decoding and modifying tiny snippets of an exe, but the entire game? Fuhgeddaboutit.

It would be far easier to clone the game based on what you see on screen than to decompile and reverse engineer it (and cloning it based on what you see on screen would be pretty dang hard). If you love the game, you'd be better off making your own game that takes inspiration from Jericho.