I really dig the art and music of this game, it has a nice atmosphere to it, great job!

Aw man that's it? There is a lot of promise in this concept, but what's there is fun, though I wish I could edit sound settings in-game I understand that would be another button, probably

The presentation is extremely nice, and it feels like I'm playing the demo of a paid game. There are a few things that need polishing though, and besides the other things the other comment has listed, I noticed a few bugs. 

There's a bit of jittering whenever the player character stands on top of a one-way platform, which is a bit strange, but doesn't affect the gameplay. The top left blocks that are reachable by jumppad on levels 2 and 3 have no collision, which I initially thought was intentional and there'd be a secret up there, but I really couldn't find any, so I'm assuming it's probably an error. If you press time-stop enough times in a row, the total time decreases down to -0.02, and everything is eternally stopped (as shown in the picture), which requires a death to reset. This also seems to carry over if you finish the game at -0.02 and hit continue.

Some suggestions I have are to make it possible to unstop time by tapping the z key while it's stopped (although you might not want to implement it if you're going to use the inability to resume time in a puzzle) and to let the moving platforms keep their color. When I first jumped on it, I thought it was stopped, but the platforms still moved even though they looked the same as everything else that was stopped. Since the player and the platforms both move, it seems like an inconsistency that the player keeps their color but the platforms don't. 

Overall, it was a good game, and good luck on finishing developing the game!

I have just played it. :)

Semi-on-the-fly remarks:

1. I think it would be a good idea to indicate the Z key for menu selection! I only guessed it thanks to the screen capture that forebodes it.
2. Z works on my AZERTY! I was afraid there would be once again a QWERTY-only convention — which is not too cumbersome thanks to the 3-button constraint. XD
3. Three languages! :o Nice. :) Conozco español, but ‘Noku’ is foreign to my knowledge…
4. This is really a detail, but it would be good to have an musical excerpt to know which music volume to set; because of the constraint, we cannot go back to the menu to change it without relaunching the game. X) I had to, as it was too loud on my system.
5. Going from 30 to 20 or 40 for the music volume triggers the impossibility sound; maybe because my sound volume was set at 30?
6. I like the music. :) It gives a sense of adventure.
7. I also like the coherent greenish colour hue you chose.
8. In the third screen (or about there), there is a trampoline in the upper-left corner, but it does not seem to be reachable?
9. Nice, two possible paths!
10. Some minor collision problems when the character reaches the bottom of a moving platform; maybe is it even expected?
11. Ah, reached the end. I like the dramatisation: the music fades away, there is a zoom and the character pauses. :)

I think the concept is nice and surely has a lot of potential; Braid is a good example of what the {platform + time manipulation} combination can yield. In this prototype, the way time is used is straightforward (either hold a door open or maintain spikes deactivated), but I am sure you can come up with elements that will interact in an interesting puzzling way with the main mechanic.

It is also witty to make up for the jumping button through trampolines. Maybe you can also vary the elements that help the character move, adding even more to the puzzles. :)

In conclusion: there is already much effort put in the presentation of the game, I think it could be extended with new mechanics in the future so that it gets very interesting. What mechanics you choose depends on how much action and how much puzzle you want in the game; it could go either direction, or both!