Note: This game is EXCLUSIVELY in French. There is no version in English, so don't ask. You can figure out the puzzles, it's just a bit harder to understand what's going on. Even so, if something isn't covered here, that means it's pretty darn intuitive and you should be able to figure it out without risking losing the game. This isn't Arcane; there's no time limit or anything waiting to grab you. Hints marked with a * pertain to puzzles you might have to start over and/or will pull your hair out over, so it's really worth taking the time for a hint there. But I refuse to give answers away.
To use items or give items to people or things, drag the item selected to those things. To open an item yourself, drag it to your character. To use your items on each other, open your inventory (press the red button) and drag one item on top of the other. To pick up an item, click on it. (Sorry, but I hate it when people go "How do I use this on this?")