For Luna project, I’m searching games to consult, and Soul Bubbles is a very interesting example, for progress, balance between pleasure and difficulty, cohesion between worlds (which have nevertheless specific identities).
It’s a DS game where we must escort spirits, protected by a bubble, until level’s end. The protective bubble is directed by breathing (but with stylus), and we must avoid traps, ennemies, and resolve puzzles.
The game fits really to device, all is possible with stylus and it’s very ergonomic : we control quickly actions (cut bubble, merge…).
In each world (8 in all), every game mechanic is introduced in an intuitively and slowly way, and each world has a specific identity (gameplay, graphic and sound). And there are also very pleasant moments, where there is no action to do, just let us get carried by the wind…