Though your game don't have so many graphical demands. A lower resolution option will help, but maybe the overall optimization will really improve the performance. I don't know Unreal, but in Unity there is a lot of resources available to just attach to the objects, each one will demand a lot from the hardware as complex physics, interactions, collisions etc.. I am personally avoiding to make large use of these awesome things because I saw many developers struggling to sell their games just because the overall hardware around the world just can't run it.