ok, so I might've gone a bit too far towards challenge and skimped on the atmosphere, but
here's my level. I tried to at least pace it decently (for example, there are no save points until the 5th or 6th screen, when stuff starts to get harder). I kinda subvert that, though.
My original concept was to make the player have to die to beat the level, but then I found out that you have to touch the checkpoints for them to activate, which made the idea impossible. I was really bummed out about that. But by the time I figured that out I was a few screens in so I decided to finish anyway. Congrats to anyone who makes it through without getting frustrated.
edit: sorry for the billionth edit, I just wanna elaborate on what I was thinking with this level.
The first screen is one of those "see the end of the level from the beginning" scenarios that I've seen other people do and I really like because at the end of the level it's kind of a reward to be on the other side. The second screen gives you two options for places to go, I'm assuming that most people will move right, which leads to a little jumping puzzle and then, abruptly, to death on the next screen. I thought it would be a good idea to trick the player early on, especially because you tend to expect death to be coming on the next screen when you've just been through a little jumping puzzle. It's a bit mean of a trick early on in a level, but it can be avoided...I mostly wanted to reward the person who decides to go left, since that's a less common choice.
After going left, there's one longish jump on the first screen and then a leap of faith on the second screen. This is the first time that you have to take a leap of faith without knowing what's coming next so it's followed with a little break: two screens of what the player previously saw, this time on top of the level. I chose to just let both of those have no jumping puzzles so the player could either see that they were rewarded for going left, or to finally be on the right track and see their previous failure. Both of those screens also have weird pseudo block art in them that I wish I could have found more space for after that.
On the fifth screen, there's a few descending jumps, and then you have the choice either go right or jump left. If you go right, unless you go left quickly you get stuck and have to fall down a pit and die. If you go left, you discover for the first time that you can jump above the blocks to get to the next screen.
The sixth screen has the first save point, but you have a choice to go to it or try to do some jumps. The jumps let you shortcut another frustrating screen that you have to go through if you get the save point, but there's also a risk of you dying and having to start the level over again instead of from the save point. So here, there are two choices and both of them are acceptable. I like this part a little better than what I did previously, just punishing the player for going one way.
Once again, you need to take a leap of faith to the next screen, and another leap to get to one side of the screen to the other. This begins the last major jumping puzzle. I let you save there because this part is harder. The first side of the screen involves jumping back and forth from one screen to another to get to the top of a structure. You can also do this without having to jump from one block to another, but I thought it would be reasonable to give the option of using the blocks on this first puzzle. Once you're through there, you go to the next screen which is just a column 1-thick wide of blocks with a save point. Here, you don't have any blocks and you have to jump really carefully to get to the top. This part is frustrating, but it's the last jumping puzzle and there's a save right there so there's less punishment for screwing up.
Once you make it through that puzzle, you have to walk above the level once again, this time for a whole screen. The walking takes you back to the first screen and sends you right down a slide to the exit. You can choose to jump over the part with the slide and walk back to the beginning of the level, but there's little point in doing it. I just thought it would be a nice little easter egg to have it be possible.
Anyway, I'm sorry if I went into way too much detail here, I'm just trying to explain my thought processes because I thought it might be interesting to someone. Hopefully it is.