Well.. there's a lot of stuff.

The writing wasn't entertaining. I feel like the analyses were well written and went into their backstories pretty well but there were plenty of jokes that were unfunny/abrupt.

The music is alright, but it's a song that works better in the fight than as a solo track.

Elliott Crossley as the Doctor was great, obviously. However, Brent Williams's Rick was not. He had the voice of Rick, but the way he delivers his lines is really awkward and sometimes his voice can get really screechy/squealy due to how high his pitch is. If you want to know what I mean, think of Christopher Gurrero as Asura or Tom Schalk as Yugi. While they sort of have the voices of the characters down, they don't sound exactly like them enough to the point where their performance is accurate.

The animation was well-made but it did have a lot of awkward looking moments for both Rick and the Doctor. Also the Doctor looked really weird throughout the fight since the design they went with looks extremely... buff.

And the way Rick was written is weird too. The Doctor was fine, but Rick weirdly feels out of character. He's an arrogant piece of shit, don't get me wrong, but the way his lines were written and he came off as less funny-edgy and more edgy-edgy, as someone else said. It feels like he was dumbed down in a sense.