Greetings! I'm working on a solarus game where you can control 3 heroes that have different abilities and weapons, and switch between them using the menu (or pressing space bar if they are in the same map). I have not worked much on the plot, but I will explain now a bit about the gameplay.
The main heroes will be:
-An archer, the only one who can jump over holes (and water and lava), and has a bow with wooden arrows, a crossbow with metal quarrels, a shovel (that can be used to obtain metal quarrels from the ground and the usual uses), a sickle that can be used to obtain wooden arrows from certain plants (which unlike the sword, cannot cut solid plants), running boots (that can be used with the ability of jumping), etc.
-A swordsman, the only one who can swim on water, and uses short range weapons like a sword, spear, shield, a magneto (that can be used to deflect the metal quarrels a certain angle, and other uses), etc.
-A mysterious wizard (with short range spells) who has lost his memory, that can throw fire (to burn plants, or to combine it with the arrows of the archer to produce fire arrows), throw electricity (which paralizes enemies, turns on machines, hurts water-type enemies, and also can be combined with metal quarrels to electrify them), swimming in lava, mind reading of npcs (and even the other heroes), teleporting all heroes to the entrance of the dungeon or certain place of the map, etc.
I have also finished the scripts to change control between heroes, but it remains to make the menu to change between them from different maps. In maps where one of the main heroes is left, the position and state of everything must be saved to avoid solid entities to reappear overlapping some hero (this is necessary, but easier than it seems).
Also, I made a script to carry custom entities (although I still have to solve some problems and improve it). These portable entities can be thrown from one hero to another (useful if there is a hole or thin wall between heroes, or if they are moving in platforms, etc). Keys will be custom entities that will be carried, which is something unusual, and will allow to make enemies that steal the key, or annoy in other different ways (like changing the color of the key, but I don't want to give more spoilers). A key will open only a door of its color. There could also be magnetic keys (to use the magneto with them), and other types. Some portable items can be used to push buttons, and they are always moved by platforms.
The symbol of the game will be a clover (instead of the triforce), there will be secret clovers in the island that can be collected for something good to happen (like the secret seashells in Link's awakening), and a dark/light magic clovers which will be part of the main plot.
There are huge possibilities for the puzzles in a game like this. But the hardest part will be to design the island (not the dungeons), since sometimes the heroes will need to take different paths to arrive to the same place, and other times you can cross some road if you take two or all the heroes at the same time in that way (cooperation between them is needed). There will be parts of the game when you don't have the three heroes (at the begining you only have one of them). Etc.
This are the main ideas for my game. This is maybe too ambitious, but it is possible, and the hardest part of the scripting is almost done, although it still remains to make most of the graphics and start making all the maps and dungeons. I would be grateful if someone wants to cooperate with this project or contribute with some more ideas.