I have just played it. :)
Semi-on-the-fly remarks:
- 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.
- 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
- Three languages! :o Nice. :) Conozco español, but ‘Noku’ is foreign to my knowledge…
- 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.
- Going from 30 to 20 or 40 for the music volume triggers the impossibility sound; maybe because my sound volume was set at 30?
- I like the music. :) It gives a sense of adventure.
- I also like the coherent greenish colour hue you chose.
- In the third screen (or about there), there is a trampoline in the upper-left corner, but it does not seem to be reachable?
- Nice, two possible paths!
- Some minor collision problems when the character reaches the bottom of a moving platform; maybe is it even expected?
- 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!