The boss battle with Dracula replicates the prologue dialogue from Castlevania: Symphony of the Night word-for-word, with The Kid replacing Richter. And then... he throws his wine glass at The Kid, killing him if he doesn't dodge it in time.
Didn't escape the room with the Tetris pieces in time? A giant pill from Dr.Mario smashes you and it fills the whole width of the playing field to boot!
In a certain level (before Kraidgief, IIRC), there are some spikes at the bottom of a room, but they cover only a small part of the floor. You'd think you could jump off safely... and if you try, the spikes get up on their legs and place themselves right below you.