QWOP is Bennett Foddy's 2008 browser game and one of the most famously difficult things on the internet. You control a sprinter at the Olympics, except you don't control running — you control four individual muscles. Q and W drive the thighs; O and P drive the calves.
The result is that walking, a thing every human does without thinking, becomes a genuine motor-skills problem. Most players never pass ten metres. The hundred-metre finish is a real achievement, and the game's difficulty is entirely honest: nothing is random, and everything is your input.
Bennett Foddy, in 2008. He later made Getting Over It with Bennett Foddy, which shares the same interest in deliberately difficult controls.
Because you control individual muscles rather than the runner. Walking is coordination your body does automatically, and the game takes that automation away.
Ten metres is respectable for a new player. Fifty is good. Finishing the full 100 metres puts you well ahead of most people who've ever tried.