For question 1, the two blocks at the bottom of the screen are an okay indicator of going to the next level, but you might want to make those blocks a different color so that the player can tell that that is where you have to go to get to the next level.
For question 2, the game layout is kind of confusing, as it is just a bunch of shapes thrown together, with no real indication of what to do (I am not able to interact with any of the shapes, since I don't know what button to press for what), and it only takes up a small fraction of the screen space. Yes, continuous collecting/strategic trading would be a fun concept for a game, as it would be engaging to the player.