Ask HN: What are minimal validations to be done before starting on an idea?

I am at a hackathon, there are several ideas being proposed. I can contribute as a developer.

But I want to make sure, I choose the idea which makes most sense from business POV.

So what are the minimal checks that I should do, to validate that the idea is good enough, and I can proceed further.

So the question is what minimal Qs should be asked before to validate the idea?

Basically it boils down to How the need analysis/ideation stage should be approached, the basic checks.

Thanks!