Daughters 4th birthday......

Hey mommy's! Daughter is turning four soon and were having a party next weekend and i was wondering if anyone had any cheap activity ideas? Were having the ghests kids open 1 present, which will be a nerf gun and having a nerf gun fight (they're all 3- 5 years old by the way) any other ideas?

Bf was saying an egg hunt (Easter eggs filled with candy) would be fun even if it's not Easter

Any ideas ?

Idk if it matters but the theme is mermaid

Itll mostly be girls but there may be 1 or 2 boys