FallenArts has done some wonderful level design as you can see here with a wide variety of enviroments for this game, I couldn't let it go unnoticed. We are still working hard but I am afraid we wont have a demo out for a long while so hopefully you guys are patient.

But I can confirm some things...

There will be an item shop to purchase upgrades and bonus content.
The in game image gallery will have various game art some of which is unlock-able via the shop or achievements. That hints at an achievement system.
With the visual experience we will have a dialog system this gives the game some narrative, this is to satisfy those who enjoy textual content as part of the games "story line"...
We have 6 levels but the game is designed around 8-9 levels and many have yet to be put in. Each level will have a boss and different enemies to "fight".
We have around a dozen different enemies already in the works and plan to add more.
You can sometimes access a partner dolphin to assist you at various stages their gender is selectable by user as well as your own player dolphin gender.

I posted only clean screenshots sorry :P