Mike: I can't keep burdening Lisa forever, but I do have a Happy Box and nice-bodied girls like Nan and Linda to keep me company, so I'm pretty happy in my own way. Nyahahahaha! Linda: I'm sorry, Mike, but that's called sexual harassment these days. Mike: This is a hard world we live in now. How disappointing.
Wess Dance! It's also possible to replace Wess in that scene with several other characters, but they're not animated to do the dance, so they end up doing something weird. In particular, Lucas appears to be mooning the door.
The best part is that this makes the door laugh, allowing you through.
This bit in Chapter 2, when Kumatora accidentally triggers a trapdoor that sends herself, Duster and Wess plummeting down a pit.
Wess: PRINCESSSSSSSSS!!! Kumatora: My bad.
At one point in Osohe Castle in Chapter 2, Duster is required to drop a heavy ball from a statue onto a cracked spot on the floor. Dashing into the statue from the opposite side will allow Duster to continue as normal. Dashing into it from the side of the cracked floor, on the other hand, causes Duster to get smooshed, resulting in a Game Over.
(upon examining one of the machines) " 'Dance Dance Business Kimono'. What kind of game IS this?!"
Any time you use an oxygen machine when you're underwater. Just so you know, the "oxygen machines" look like mermen with huge feminine lips. And they give you oxygen by kissing you. The whole party blushes in an embarrassed way when you're done.
Talking to Nana, the girl by the beach. Before talking to her, she warns Lucas that everyone hates her for talking too much, and when you ignore her warnings, she goes of on a long talk about music and destiny, after which it cuts to black and back to the screen, where Lucas and Boney are dizzy from listening to her.
The Pigmask Guard asleep on duty at the start of chapter 7.
There's a brief moment in the official gameplay trailer when Travis comes across a dumpster while he's dragging a fallen ally behind him- and then glances at the load weighing him down as if contemplating the obvious.
Every time an enemy did an odd action during battle, an example being the New Age Retro Hippie who used a ruler and can now measure the lengths of things more easily!
While many of said actions were useless, there are the occasional few that are really weird AND have an effect, like when that same New Age Retro Hippie taking the time to brush his teeth in-battle, making his teeth so bright that they paralyze you. Yep.