I remain very easy to impress with something that glows in the dark. Show me a perfectly ordinary plastic dinosaur, then turn the lights off and reveal a faint green dinosaur, and I will be pleased. The dinosaur has gained exactly one ability. It is an excellent ability.
Part of the appeal is the little reveal. You know what is supposed to happen, but there is still a moment of “oh, there it is” when the room gets dark. Ceiling stars, a ghost-shaped ornament, a suspiciously luminous keyring: all very simple objects that become slightly more interesting once the lights go out.
I especially like the stuff that looks almost normal during the day. A small figure on a shelf quietly waits for its evening shift. Then darkness arrives and it becomes the least threatening supernatural presence imaginable. A tiny glowing skeleton does not need to frighten anyone. It can just stand there, doing its best.
There are plenty of impressive things you can put in a room. I am happy to leave a corner for something whose entire contribution is being faintly green at bedtime. Give it a cheerful shape and a suitably daft expression and it has already justified its place.

