Soulslike
Also said as Souls-like, Soulsborne
Slow, heavy third-person combat, where stamina limits every swing and enemies have long tells you must learn. Death drops what you were carrying where you fell. It promises that hard things can be beaten by paying attention.
Difficulty comes from commitment, not from fast reactions: every swing locks you in. The dropped souls make walking back to the same boss feel tense and worth doing.
Say it
“Soulslike rules: every attack and roll spends stamina, a boss wind-up lasts at least 600 ms, and dying leaves your currency at that spot. You get one chance to fetch it.”
Where you’ve seen it
FromSoftware's Demon's Souls (2009) and Dark Souls (2011) set the pattern. Resting at a bonfire in Dark Souls saves you and brings the enemies back, and if you die before reaching your dropped souls, they are gone for good.
Not to be confused with hard game
Plenty of hard games are not soulslikes. The genre is a specific set of rules: stamina, committed attacks, checkpoints that bring enemies back, and a run back to what you lost.