I personally like the fact that there are no instructions or tutorial. It's entirely possible to learn how to play intuitively without someone holding your hand. And the fact that the gameplay is simple enough to allow this is a testament to good game design. Although... maybe there should at least be a "Click to Start" dialog over the puzzle when you begin.
Fighterlegend, it doesn't matter what letter the word starts with. Only the first sound of the word when you pronounce it counts. And it is "A unique", NOT "An unique".
There's no way to cancel placement of a trap once you've installed it. Also, pressing menu while you're in trap placement mode and selecting "No" can sometimes put you outside the shop menu, trap placement mode, and fighting mode, meaning you're stuck with no way to advance.
Maybe you should fuse the two difficulty levels through some sort of medal system. Each level would have 4 medals: 1. Finish level under the weight difference. 2. Finish level with minimal weight difference. 3. Finish level without ever breaking weight difference. 4. Achieve 2 and 3 in one go. Earning at least one of these medals lets you through to the next level.
Bah, there's an uncontrollable element of luck in this game. Sometimes, you connect two ships, and instead of crashing, the two start twirling around endlessly until they crash into you. And then it just gets more and more out of control, with too many targets and not enough time to properly dispose of them all. It's repetitive, it's annoying, and it gets a 2.
I think you should change how the controls work when control is sideways. Have up move up, down move down, and either left or right jump (depending on gravity). What you have right now is unnecessarily confusing, and inconsistent with the way up and down gravity controls work.