Cassette Beasts is a creature collector with a substantial single-player campaign and a permadeath difficulty option.

You could also have permadeath as a house rule, which would let you play singleplayer games with traditional campaigns. For example, you could play Elden Ring or Borderlands 2 and commit to deleting the character upon death.

A weird suggestion: Keep Talking and Nobody Explodes is a co-op puzzle game about defusing a bomb. The player who’s streaming will have the bomb but stream only audio, not video, and everyone else will have to use the defusal manual to guide them to safely disarm the bomb. You’ll have to advance level by level.