The best casual games like Lemmings are Lemmings (2006), The Incredible Machine and ChuChu Rocket. Below are 5, each with the reason it is here — and, at the end, what filtering to casual costs you.
Filtering to casual means you want something you can put down. That is the whole definition, and it says nothing about how deep the game is.
What you get: A game that fits around a life. Short sessions, save anywhere, no penalty for a week away.
What made Lemmings worth playing in the first place is covered on the full list. This page is the casual part of that answer, and only the casual part.
The PSP remake, and the cleanest way to play the original levels today.
The other great indirect-control puzzler — build the contraption, then watch it fail.
Arrows on a grid, mice that never stop moving. The same panic in miniature.
Physics puzzles where you design the solution and then watch it hold or not.
If the appeal was the pressure of something arriving whether you are ready or not.
Momentum, sometimes. A game designed to be left is also a game that is easy to forget you were playing.
Specifically, these are strong answers for Lemmings that are not casual games, so they are not on this page:
The full list is on games like Lemmings — 10 picks, no genre filter.
Lemmings (2006). The PSP remake, and the cleanest way to play the original levels today.
No. Lemmings released on the PC & Modern Multi-Platform, but a recommendation is only useful if you can play it, so the picks above span platforms and eras. What they share is the genre and the reason.
No. Several of the deepest games there are — Tetris, Balatro, Into the Breach — are playable in twenty-minute pieces, and some of the shallowest demand an entire evening.
Often the opposite. Many are built around daily timers and streaks, which means stopping does cost you — the one thing a casual game is not supposed to do.
By hand. Each pick was written for the full Lemmings list first, on what the game actually does, and this page is the part of that list that is casual — never a genre tag lookup, which is how "best racing games like Super Mario 64" used to be a page on this site.
Or read the casual guide for where to start in the genre generally.