These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: A fairly minor one compared to others, but the forums have been divided on whether or not the more serious, story-driven Cocoon Academy arc is a good thing, or if the comic should stick to quick, cute gags.
It's actually more broken than it appears, it's just that a lot of the nay-sayers don't say much about it on the forums.
Did Not Do the Research: For all the points where he shows how much he knows about Nintendo in "The History of Nintendo," he makes one minor error in the song. The Virtual Boy came out in 1995, not 1994. Because of how much of his work is shown, this mistake sticks out like a sore thumb.
Fridge Brilliance: Anyone who may not have made the connection, the "I'm not Jigglypuff!" may have been a Shout Out to the memetic nightmare scene from Rugrats. "I'm not Tommy!"
Many parts of the Mushroom Kingdom Carol arc, particularly the eighth panel of this strip, become hilarious after the Mario cast's appearance in Fortune Street.
The joke in this comic is funny to begin with, but it becomes even more hilarious when you realize it's exactly what ended up happening.
Moral Myopia: Yes, "Ode to Minions" is touching, awesomemusic, etc... But it ignores the fact that all of these minions would kill the player if they had the chance. They're just not very good at it. If Bowser stayed home and ordered a prostitute instead of invading another country to kidnap a princess, these minions just trying to get by wouldn't be out on the front lines getting killed. And that's not counting the non-sentient ones like the metools, which are more like attack drones (the ducks on the other hand, really aren't doing anything).
While you have points about things like the Kraken (it would have killed Ness and Co), the Metroids (mindless parasites) and Wolf's Ship, the minions thing is the whole point. Bowser's singing the song about how bad he feels about all the minions, his included, who have died.
As the ending of the song shows, its clear that the point is the heroes are horrible people for massacring millions of enemy combatants like that...but Bowser feels like a horrible person for putting those combatants in harms' way in the first place. It's about how it's Grey and Grey Morality, like any true war, not Black And White like it is usually painted.
Tastes Like Diabetes: Don't listen to Matt on this one; by webcomic standards, BitF's humor is especially light-hearted. To illustrate, this is a work on the internet for which the author once apologized because he had used the word crap in a Curse Cut Short. It's still cute.
Tear Jerker: Make sure you've read all the Waluigi in the Family strips, then read the Waluigi Trilogi, where things get even crazier. Then, reach the bottom and realize you are a horrible person for judging Waluigi so harshly.
That's right, he apparently literally can't even fantasize himself as a hero.
In real life: Matt, after having to postpone comic 400 for about a week and a half due to health problems, finally told us just how bad it was. The emphasis he puts on thepain he's in is staggering.
And Eario, the janitor of the Mushroom Kingdom. He cleans and polishes (and refuels the bullet shooters) all for his idol Mario, and the day he got a coin from a block Mario hit was the happiest day of his life. Until he was reunited with his son(?), Waluigi.
Young Dedede in the Cocoon Academy Story Arc. First he gets into a food fight by accident, is sucked up by "Pinky," and gets detention for aforementioned food fight. When he gets home he has a terrible dinner (so says the mouseover text) and the next day he's sent to Headmaster Hand's office. And then later on, he thinks that he's lost "Pinky" as a result of fighting Dark Matter...
Luigi can't fantasizeHIMSELF being the hero. Also, Matthew saying he has low self confidence doesn't help...