My twelve year old daughter recently held a slime birthday party. Games played were - Jelly Twister - I bought white plastic plates and mixed up red, blue, green and yellow jelly. I spooned jelly onto plates and placed them on the traditional Twister mat. We played as usual - but kids put hands feet etc in the Jelly. Got really messy. Digging for prizes in the slime bucket - I made up a bucket full of slime - fill large bucket with warm water and add one box of Lux Flakes - leave overnight and it will turn into slime (add food colouring at the last minute) I wrapped up party toys in cling wrap and burried them in the slime. You need a few towels on hand for this one. We had our backyard covered in plastic drop sheets which we purchased for a couple of dollars at the local hardware. Once they had finished digging in the slime we through a bit of it around on the plastic drop sheets and the kids went wild sliding around etc. Tug- o- war - we then got a tug of war rope and let them play on the slimy plastic. Girls against the boys - and the girls won.  After that they were really slimy - so we had a sit down game. Pass the Spaghetti Brains. I made up several batches of Spaghetti and added food colouring - I punched holes in the top of a yellow bucket and threaded hair all the way around it and then drew a crazy face on the front. I filled the bucket with spaghetti and added wrapped lollies and chocolates. They played it like normal pass the parcel but when the music stopped they had to dig in the spaghetti brains for prizes. In future I probably would add a few tins of bought spaghetti to make it a bit more messy. Once all the slimy games had finished we had the kids get changed. Only 1 child forgot to bring a change of clothes!  After that we ate - Pizza - didn't really want to go slimy for food but I did freeze gummy worms inside lemonade iceblocks for their drinks. After dinner we had a limbo pole, and a pinarta and some dancing. We were going to play treasure hunt by torch light but ran out of time.  At the end of the night we lit a bonfire and toasted marshmallows and told scary stories. The kids had a great time - unfortunately my daughters birthday is in Autumn and the weather was a bit cool but this would have been great in summer - In summer I would have put up an outdoor shower to wash them off before getting changed.