¿an amusement park?,well... that's very nice,in the old and the actual forum of pxlpd says the next zones from the prehistoric volcano stages,there are some casinos and bar but... well... probably different stages of differents projects looks a good idea too,for example,while the version of redeye samurai have a casino and bar stages (probably a mud wrestling tournament too),you can have an amusement park stages in your version,differents enemies and concepts between these two versions of your games.
another thing,your second island map looks very cool too,probably the first one where the 2nd stage can be probably just need a seaside forest,a deep forest with some trees stump to jump over,next a big tree where is the secret zone but near that big tree is a garden with a mansion in the distance and a beach to get to the underwater stages to conect to the pumpkin kingdom but... mmmhhh... saddly,we never visit the interior of eleonor's mansion,just her garden from the 2nd boss fight.
well... i wish good luck with your project too chip1155,they looks awesome and lovely too.