(this post is a feed post from my comments on reddit)
r/startups
Document your brand name, get the domain name and related, but you can probably avoid actually registering the trademark for it, until you have a few commercially successful releases, that would financial justify this as a business for you.
as for your headline question – Is it a startup if only single person is working there? – it depends, if you want to follow thr strict venture capital definition of a startup what actually makes a startup is unit economics that allow for exponential growth.
Is it a startup if only single person is working there ?
byu/surealme instartups