This is a mainstream shounen battle manga straight from the training books, with no new elements at all, not even trying to be original. A manga that is only created to generate profit by running as long as possible, clinging to it's life while repeating the same stuff over and over again.
It starts off as some silly comedy, then, at some point, it notices that it doesn't work anymore and turns into the most mainstream battle manga you could imagine because it simply goes into the endless powerup -> stronger enemies -> powerup -> stronger enemies -> powerup cycle.
And more than half of those powerups happen for some arbitrary reasons (aka plotarmor) without any form of training/buildup before.
There are quite a few plotholes, especially during the future arc.
As for characters, there's no deep character development, not even for the main character. It tries to make you believe there is, but when you look at it closer, there isn't.
One character (chrome) seems to be created to draw pity from the readers, I don't know what's 0supposed to be accomplished by this, but she exists only for the purpose to be possessed by the strongest character in the manga while fighting, she herself always gets overwhelmed. She had absolutely no connection to tsuna prior to being chosen as the mist guardian and now that the strongest character has his own body back she is even more useless.
Really don't get the author for treating the only interesting character in the manga like garbage.
Bottom line: it pulls of the shounen mainstream battle ok, else it wouldn't have run this long. But it should end soon if it wants to keep even a little bit of dignity.