I'm glad you like it so much you want to have it with you on the go! =)
Unfortunately I don't have any space left in the cart to add instructions. Early on, I decided to focus on graphics, number of levels, and the variety of items and interactions, instead of adding a tutorial in-game. However, the way I set up each level and the progress of the levels are meant to give you an understanding of the mechanics. For example, the first level is purely just to let you understand the style of movement, no items, no enemies.
Then when each item is introduced, the first couple levels are simple with limited choices so that you focus on learning to use the item instead of trying to solve the puzzle.
Since I can't add tips to the game itself, I can at least share a couple here!
Tip #1:
If you are struggling in later levels, go back to earlier levels and try to get 3 diamonds. Those earlier 3-diamond solutions usually require a trick or mechanic that you need to know just to solve later levels. So going for 3 diamonds is actually a way to learn the game faster and make later levels easier.
Tip #2:
Stuck on a level? Try everything! You'll be surprised with creative ways that items interact with the room, objects, enemies, and even other items!