Bad traps and ladder mechanics
There really needs to be a way to get off ladders without jumping (inevitably into the spikes that are placed just so they hit you if you even try and exit the ladder in the right direction). This is alright on the earlier parts where this sort of trap appears because it can be avoided by making smaller jumps and going off the very bottom of the ladder but in 1-25 having to jump between the ladders with the spikes in between just makes it impossible. Also there's no reason why spikes should do 2 damage instead of 1, its just completely unneccesary.