I had a go at the downloadable version also, and it worked and i managed to bet the game, with 2:44 left on the timer :D
Although my platforming skills aren't the best, the game was enjoyable and overall I had fun.
The last jumping section was a bit to hard, in my opinion. It was not very clear what was the intended method/path there, in regards to using the dash. I simply double jumped on the middle column all the way to the top.
Had a few issues with pushing the button, sometimes I was landing on it but it would not press down.
Also consider to give the player a feedback for any action performed, especially if the result is not immediately obvious. As in this case try considering having the button to stay pressed or have an audio cue so that the player will know that it had an effect and that it is not bugged or stuck.