I completely second Castruccio's comment on the font.
We've been conditioned to have different fonts conjure up different emotions and thoughts. For a game based on a comic book, or one supposed to evoke feelings of comic books, I'd expect to see the font from Nick's comics (comic book font is instantly recognizable). Casino Hand belongs to a category of fonts that evokes feelings of whimsy or childishness. Any games that involve children heavily or take place in a dream world could get away with using these fonts. Using the 'wrong' font for a particular game can contribute to making that game seem amateurish in the eyes of players. While not a huge deal in and of itself, it's part of an ongoing image that the players develop as they play the game. Using a childish font in a serious game may damage the image of a game more than using a 'serious' font in a childish game, since we're used to seeing 'serious' fonts everywhere. This is part of the reason why using whimsical fonts is more risky -- since we're unused to seeing them, they stand out more.
I would say that the Casino Hand font was probably too whimsical for Valley 2, giving the game an unneeded lightness. However, there was also a tonal mismatch between the strategic and the platforming parts of the game: while the overworld showed a desperate struggle for survival against a fearsome, raging foe, the platforming sections featured some very ridiculous-looking creatures (in particular I'm thinking of the sideways-walking crabs, but other examples exist). The game font therefore seemed more in sync with the tone of the platforming sections.
I haven't played Skyward Collapse, but from the video, it seems like Casino Hand is possibly too whimsical for the tone of the game, unless it IS supposed to be quite whimsical. I'm also not sure about the choice of the comic book font unless you'd want the game to feel like a comic book. When you play a game, you dive into its world and generally take it and its rules seriously, even if the world is mostly silly. Silly fonts serve as a constant hint to the player that he is inhabiting a silly world, and IMO serve to break immersion.