Begin in large hub area aboard a pirate ship that has become Yooka and Laylee's adopted home. It has 'Bat Ship Crazy' painted across it.
Butterflies: Eat with Yooka's tongue for health, or collect to refill your power meter. Yooka's roll uses up the power meter... i.e. you can't roll forever like with Kazooie's Talon Trot.
200 quills are scattered across the world, spread across race circuits and along minecart tracks etc.
'Tokens' (Playtonic Coins?) unlock 8 multiplayer arcade games. Once unlocked they can be accessed from main menu and support up to 4 players.
Play Tonics must be earned by achievement-style challenges (e.g. kill 100 baddies); They are optional, so apparently not integral to completing the game. One reduces the power consumption of Yooka's roll, another lets you collect distant quills with Yooka's tongue etc.
Ghost Writers: they all behave differently. One hides, one attacks you, one needs to be chased and caught etc.
Unlocking a world gives you a free move from Trowzer; you can also buy additional moves via quills.
(Jungle opening area: I'm unsure if this is the hub area with the pirate ship; the article was a tiny bit unclear)
Transformation is a plant that lets you speak to flora that otherwise ignore you.
Spitting a 'Splash Berry' at a rain cloud creates a waterfall that fills the riverbed below, thus opening new areas. Spitting a 'Frost Berry' will freeze the river and create a racecourse across the ice.
Laylee's sonar blast move triggers invisible platforms to reach to areas.