My wife was playing and asked if she can select a female character. I unfortunately told her no. She is asking for something cute. Anything you can do to please her would please me.
An effect from being overburdened could cause tripping and stumbling down stairs.
Expanding upon the in game fishing summoning a shark, other tiles could also be a hidden danger themselves. Trees could hold a hidden snake, a bone item is really a skeleton who spawns, or a rock is a sleeping golem
Traps would be a possible addition. Quick sand traps on quick sand, cave in traps, traps left by previous people around their shelters.
Monsters could exist in multiple stages such as zombies killed to reveal the skeleton.
A rats nest, rabbit hole, spiders nest, or ghost ship could spawn monsters until destroyed.