Half-Life 2: Lost Coast is a short, free standalone tech demo originally created to showcase the Source engine’s new High Dynamic Range lighting. Players control Gordon Freeman as he climbs a rocky coastal cliff, battles Combine soldiers and headcrabs inside an old monastery, and uses the gravity gun to destroy artillery emplacements and a helicopter. Most people play it as a quick 15-30 minute nostalgia run through Steam, often enabling developer commentary or toggling HDR to see the original visual showcase that helped define early 2000s PC graphics. At 4K, the modest demands of this 2005 DX9 title change because the resolution dramatically increases pixel throughput. The HDR blooming, bright sky reflections on water, and detailed stone textures become far more demanding on the GPU while the CPU workload remains light. This scenario matters because 4K makes the aging assets look surprisingly sharp, but it can expose subtle engine-level inconsistencies if the graphics card lacks headroom for the post-processing effects. Common pain points for 4K players are outdated drivers on very old GPUs or attempting to run the demo on integrated graphics that struggle with the high-resolution framebuffer. Before choosing a PC, understand that the real priority is a modern GPU with at least 12 GB of VRAM and strong shader performance, paired with enough CPU and RAM to keep physics and AI responsive while the GPU handles the visual load.