As someone who is starting to dabble in the Indie Game space this is all great advice, except I think "9. Falling in love with your work" should be reworded. I think the title of number 9 and what they are trying to convey do not exactly line up. They pretty much mean don't b ignorant with your time or with taking great advice, to only have that hurt yourself. As far as the literal title of 9, I personally think you SHOULD fall in love with your work, because that's how passion can pour out to make a product truly great. Other than that, good list! :)

It should read something like:

9. Letting your love of your work blind you

This is really true in any creative field. Publishers receive manuscripts all the time from authors who demand that nothing in it be changed, some going so far as to claim that it's a product of divine revelation.

This goes for any creative profession where you often work solo or within an echo chamber.

For me it's basically "Keep your ego in check. If you can't do that, learn to listen instead of defending"

I think a really important one is missing: getting feedback early and often from players. As soon as your core game loop is done, you should play test it with people from within your target audience (we often use lego and cardboard or really simple Unity prototypes). Then do the same in a regular rhythm (e.g. weekly) while you implement, refine and polish.

Not sure that most of these are unique to game studios, but certainly are true of most small shops. The feedback one in particular is crucial - if you can find a way to get useful feedback (beyond just "it's good" or "it's bad"), you will be a mile ahead of most folks starting out.

Getting into the video game industry was the big mistake in the first place.