To add to what's already been said by Namida and Dullstar:
Having ideas is a great thing, it means that you're an imaginative person with a vibrant mind that's firing on all cylinders. This is a great start!
It's also good that you're bringing your ideas to people with more experience and knowledge, and asking for help/advice/feedback. That's an important step, and well done for taking it.
However, since you appear to have many ideas about lots of different things, my advice (if you want it) would be to choose one idea and pursue it for at least one month. Put ALL other ideas aside in favour of whichever one you've chosen. Let it grow and develop, and take it as far as you can on your own before approaching anybody else for collaboration purposes. That doesn't mean you can't discuss it during that month, but don't expect anybody else to contribute anything just yet.
And, don't be put off by not getting the response you wanted. Keep going with it if it's an idea you truly believe in and want to pursue.
To respond more directly to the idea in this topic: I like the idea of a Lemmings-themed OS, it's an interesting concept.
Some questions:
Are you wanting this to be an actual standalone native OS, or more like a virtual OS running on something like Windows or Linux?
How would it differ from any other OS (Windows, macOS, Linux)?
What would it offer to Lemmings fans/players that would attract them to it?