I'm trying to figure out what parts I should buy to get the cheapest system possible that can play my game "you found the grappling hook". Has anyone played it on an older system with any success? What kind of graphics card, cpu, etc do you have?

My computer is old but not very old -- about 4-5 years. GeForce MX 4000 PCI (not PCIe) video card, 2.0 Ghz CPU. It ran fine for me.