My game, having gotten the 9th most ratings out of every game in the jam, has a lot of criticism on it's page. Some suggest things I agree with, some I don't. But I never, ever, ever go off on someone, or tell them their opinion is invalid. I tell them 'thank you for commenting', then acknowledge their criticism. One example: The Neon Shark commented: "Neat! One issue I had with the game is it feels 'too zoomed in'. You can’t really get lots of context for the map, just what’s immediately around you. The safest way to progress in the game seems to be to go very slowly to make sure you see all the terrain. I didn’t get the sense that there was an alternative play style to “slow and safe”. Since you can’t SEE anything you pretty much have to move slowly or memorize the map…"
I responded with a "I agree", and I acknowledged his criticism. Then, afterward, I said, "Thanks for playing and leaving feedback!" to let them know that commenting on my game did help me out.
I haven't seen anyone personally on this site, but I know some people on the internet will go off on others whenever they get a critique, or comment. This is the absolute wrong approach. The person took the time to play your game, or experience your creation, and they left a comment explaining what could have been done better. That shows that they became even slightly invested in your game, finding ways to improve. Punishing this with yelling and bitterness will be sure to get people to not come back.
As a 12 year old, I know the internet is a dicey place to be in, and I never know how someone's going to act, and more importantly, how I'm going to react. That's why I tried as hard as I can to be open-minded, and respond well to critiques.
Play my game, and leave criticism of your own: https://ldjam.com/events/ludum-dare/48/dungeon-painter