Honestly, one thing that would greatly increase the game's value to me would be the ability to save progress midway through a run.

That way I wouldn't have to sit down and rush through it in one go, I could take my time and do it a few levels at a time.

Do you mean one run to beat the game? Because it's confirmed that you can go any planet when you want, without starting at the first one. Arcade Mode would be the way to go if you want to do it in one run. Well, "confirmed" by that youtuber, that's what he said.

I didn't catch that bit. Is the video still up? And could you give me the timeframe where he says it?

Don't know if the thread title was intentional but I got a laugh. This is a actually being sold as full price title in my country so that is worrying.

It's private now :(. I think he wasn't supposed to publish the video that early. But I'm pretty sure he said something like: "in main game mode you can explore the planets freely".