I've always thought that Chapter 3 was missing something. Something that the previous Chapters, and even the original Undertale had. I think I finally figured it out, and let me tell you, it's quite ironic.
Chapter 3 is missing freedom.
Ironic isn't it? A running theme throughout the entire game. Allow me to explain what I mean. In the previous Chapters, you were free to explore the entirety of the Dark World without at your own pace. Both gave you plenty to do apart from just progress. Chapter 1 for example lets you fix Top Chef's Top Cake in exchange for a Spin Cake, or stop by the tutorial masters for neat tips and tricks. If you'd like, you can back track to the prison for some neat lore. And once you defeat K. Round for a second time, you have the entire Dark World at your disposal. Chapter 2 also give you things to do apart from progressing. More in fact. You can find blue checkmarks for Hacker, backtrack to the dump and buy some stuff from Spamton. Talk to NPCs for lore or funny dialogue. And of course, both of them have their secret bosses. Even Undertale gave you complete freedom once you reached New Home.
Chapter 3 though? You've got extremely little to do. Tenna kinda restricts you to his gameshow, and even in the Green Room, your options are limited. Sure, you could replay the minigames in an attempt to perfect, but it would just get repetitive. Plus, you're even more restricted if you don't S, T, or Z rank on the board, as it locks you out of backstage without it. the only freedom you get is after you escape Board 3, and even then, it feels like a glorified line from A to B. Sure, there's stuff to do along the way, but there's ultimately no reason to go back, or explore places you've already been. Heck, you don't even get the option to go back until you loop back to the Green Room, which again, if you didn't get S, T or Z rank, is pretty worthless apart from progressing the story.
I actually find it quite funny how FREEDOM of all things is the missing piece. I wonder if Toby did it on purpose...
Don't get me wrong, Chapter 3 is still a great chapter. It's just missing one thing. For me at least.