Tenma, I guess he's alright for a protagonist. He does seem a lot more enthusiastic though which is odd. Comparing that to Endou, he doesn't make sense. At least Endou's made sense when he saw Daisuke's notebooks and wanted to play more, whereas Tenma was saved, which I guess makes sense.
I wouldn't mind if he was a little different in that sense, somewhat like Kabeyama maybe personality wise, as in he's not exactly confident in his abilities but learns to overcome that and play to the best of his ability. That'd also make a lot of sense for his keshin to come out at the time that it did.
Apart from that, I do like him, but I guess they tried to make him over the top, and didn't pull it off like they did with Endou.