It’s rude because avolcano is clearly excited about this premise and rodly is just ridiculing his/her excitement. There’s no objective basis to what is incredible.
I do wonder what is so extraordinary about having achievements in apps and how this would be a very difficult thing to technically achieve.
'That is an idiotic thing to say; 1 + 1 is 2, not 3' can be shortened to '1 + 1 is 2, not 3.'