These are all fairly solid. Some hopefully useful feedback:
CompositionI was trying to go for a sense of flow in this level. What I mean by that is that by the time you master the level, you'll be able to run through it without ever stopping. You can just hold right, and make it to the goal without ever having to slow down for obstacles.
The problem with holding right constantly is that after respawning at the checkpoint you almost immediately run into a spike. I think moving them apart would improve that feeling you were going for.
AtmosphereMy theme was "Outer Space/Asteroid Belt".
I liked the placement of the goal relative to the easiest path through the level. Personally I would probably have put the checkpoint just before the end of that bottom path though.
TeachingYour goal is to get to the flashing light in the upper-right corner.
Right off the bat, before the player even gets a chance to do anything, they'll be knocked upwards by an enemy bullet, the enemies will kill each other, and a single stray bullet will bounce around off the mirrors below. Essentially, the player learns almost everything they need to know about the game instantaneously as they start. However, the second half of the level then makes the player execute those actions themselves, making sure that they understood everything that was shown to them at the start.
I don't think this does a great job at teaching the mechanics.
General rule of thumb: anything that happens immediately when a level begins will not be picked up on and will only serve to confuse. By the time the player has worked out who they are controlling, everything has already happened and they're wondering what that moving blue thing down the bottom is.
Then the next two puzzles require the player to have a detailed understanding of how the game mechanics interact with each other and to use that knowledge to execute a multi-step plan.
I already knew the rules of the game and it took me several attempts to make both jumps.