Well that was rather nice. I've seen similar ideas before, and the difficulty was fairly high, but I really loved the playful level design; particularly the amount of interest you rung out of a simple spring mechanic.

+Challenging core mechanic.
+Trippy backgrounds

-Jumping a bit sticky
-Moving the window around glitches the game (in a partly useful way I might add)

@HuvaaKoodia, the window issue is specific to Windows and its event system. Unfortunately it happens in SDL as well, and I'm not familiar enough with the Windows API to fix it.

Running this on an AMD64 linux with libsfml-1.6 (Ubuntu build). Every time I started a level the character seemed to have dropped through the floor a second earlier and I just fall forever "below the level". Even moved level2.txt to level1.txt to play the second level and it still happened.

What do you mean by "MSVC build"?

IT is very much not running my my computer.

MSVC = Visual Studio. I can't figure out how to build SFML using Visual Studio 2012 (the only license I own) so it may be a while.

The mingw32 build works for some people, and not at all for others. I don't know why, but it works perfectly in Wine, my native Windows 7 install, and a Windows 8 virtual machine.

@Mark That's strange, though it is caused by a variable timestep there is something causing the game to halt for a little bit after it opens, breaking physics. Try running it with Kwin/Kubuntu or something other than Unity/Compiz.

I really enjoyed your game and the use of minimalism applied to a 2D platformer!

Also my condolences to your friends. I can see that you had a great mentor, and I'm sure they're enjoying the game you made for them up there.

I got it working on Linux after installing SFML. The jumping was extremely difficult. Sometimes it would jump when I press the key, sometimes after a short delay. Sometimes big jumps, sometimes small jumps. I tried for ages but I could never hit the first green button. I added some print statements to the main loop and discovered that the deltas varied between 16 and 60 ms! A variable timestep is notoriously difficult to get right, I highly recommend switching to a fixed timestep for physics and decoupling physics updates from the video refresh rate.

Interesting idea and well executed. Slightly frustrating at times but since it's quite an original approach, that's a risk you had to take I guess. Overall a pretty positive surprise.

Nice use of 1-button gameplay! The jumping had something wrong with it... it's hard to describe. It just feels like I have less control than I should.

... plus, for some reason, the game skipped me to the next level when I was 3 from the end. Randomly. I'm not sure how it happened. Haha

Surprisingly robust, considering the simple mechanics. Nice challenge too. =D

Can't rate - mingw build just gives me a blank command window and I can't find the MSVC build mentioned in the description.

Runs fine for me on Windows 8, 64bit. The level design was pretty good, but the mechanic rubs me up the wrong way, making things seem needlessly frustrating, especially with the occasional movement glitch in there.