To unlock the circle boss battle you have to buy and use the square shape, from the shop for 100k at extra spice, I would recommend spike crusher because it would be hard whit out it. Then use the square shape and go to the right of the map, at the end is the circle boss, after you beat it you get a key. For the square boss you have to buy the triangle shape from the shop at extra spice, again I would recommend buying the spike crusher and spike crusher+ for this beacuse its harder Then while using the triangle shape go to the left of the map and at the end you will go to the square boos, after beating him you get a key. The keys you get from thees bosses you have to use on the red box at the start. After you use the keys this will take you to the pentagon boss. After you beat him you get a new key and a new shape "The Pentagon". And last but not least the key you get from the pentagon you use on the blue box at spawn, taking you to "The Cursed World" where everything is a square. In this world you get all your score x2. I hope I helped you and have a good day. （*＾-＾*）