If you are planning some Halloween fun for small kids, the main thing to remember is not to go too scary -- some young children may be easily spooked and you want giggles not tears. Games for small children should be easy to follow with just a few basic rules and no waiting around, as kids ages 2 to 5 have short attention spans. From food games to team games, offer a spin on the games they already know.
Add a Halloween twist to hide and seek. Hide a carved pumpkin for your little monsters to find, or lots of plastic spiders (or home made card stock ones if you can make them beforehand.) Or, tell the children they are ghosts and have to hide and then sneak out and steal a pumpkin from an agreed place without the seeker catching them. This only works if the seeker goes looking rather than staying with the pumpkins, so make this person an adult. Have one child leave the room and then get someone to be a ghost under a sheet. The rest of the children can hide behind a couch while the person guesses who is under the sheet by feeling and talking to them.
Apple bobbing can be tricky for small children, so hang donuts on a string for them to eat without their hands instead. Have an adult hold the string and bob the donuts as much or as little as needed depending on the child. Different textures can become spooky if the children can't see what they are touching, so have your children sit around a table blindfolded and bring out items for them to feel. Gelatin dessert, a bar of soap, bits of wool and canned beans work well on their big imaginations. Ask them: "what do you think this one is?" and you are sure to hear answers like: spiders or eyeballs!
You've probably noticed how your kiddo prefers playing with items that are not toys -- keys and cardboard boxes -- so imagine how much fun can be had with a roll of toilet paper. Have kids work in teams to wrap one person up in toilet paper as a mummy and judge the best at the end. Turn ping-pong balls into eyeballs by drawing on them, then have an eyeball and spoon relay race between teams. Give small teams of kids a ball of wool and two chairs and challenge them to make a big spider's web -- see who gets to the end of their wool first or judge the best web.
Spider catch can be used to help them burn off energy, but you do need a big space. The catcher is a spider and each time he tags a player, that person joins his web by holding hands until a long line of children forms. Play musical statues with a Halloween theme -- children love making silly faces so tell them: "when the music stops, stand still and make a spooky face." They'll be overjoyed if you pretend to be scared. You could also have them "move like a bat" or "dance like a monster" until the music stops. Play a game of trick AND treat. Have challenges in a bag for them to pick -- such as standing on one leg or crawling like a spider. Each child has to perform a trick before getting a treat.