Here it is. The final time you'll come to Sparx World, unless you just want to visit. Before you get here though, scrape together at least 1,000 gems, unless your full gem total is already 1,000 or more. When you've completed this, go to Moneybags in the Summer Fairy World and pay him the money. Don't worry, he'll pay you back near another area.
Blue key quest
Red key quest
Green key quest
Purple key quest
So the boss here is a giant beetle. This is a true tank in the Sparx World. The only thing you can do is what you've always done in times like this, constantly fire at the beetle. Eventually, it will decrease from a tank to a semi-tank, then to a regular beetle.