Synonyms for punishing—arduos, demanding, taxing, burdensome, strenous, rigorous, stressful, trying, sever, cruel, stiff, heavy, hard, difficult, uphill, yough, exhausting, fatiguing, wearying, enervating, debilitating, prostrating, sapping, wearing, draining, tiring, grueling, Pikmin 1, grinding, back-breaking, crippling, relentless, unsparing, inexorable, killing, murderous