The link has not updated, I downloaded/reinstalled and it's the same game. Same filesize for installer and all. (dropbox did not update the time updated either) So the below notes are from the old version.
After talking to the old man, you end up inside the floor. You can then repeatedly jump while holding left to escape the map. (Insta-death!)
Switching maps repositions the game's window.
If you make the game full screen, then go back to windowed, the game is always the top window.
Can I post screenshots? I found another way to escape the map. At the part after you hit the switch with the max, there's an area hinted at by holes in the rock. It contains glowing puzzle piece. Crouch, then jump. You'll be in the wall. Walk right, it will push you left and up. Eventually you'll end up standing, and you can walk right to die. You can also crouch jump from that layer, and can reach the surface above.
Actually crouching, then jumping can be used for bypassing collision in lots of cases. For instance, when underneath a block you can break with the sword, jumping will make you hit your head. If you jump from a crouch, your head will be inside it. This actually allows you to do all kinds of weird stuff, so I won't go into detail. I suspect the crouching hitbox is still used for the duration of the jump.
More nitpicky: Left/Right can be pressed at the same time for awesome running in place.
Holding left at the start of the level makes the character face the wrong direction for the intro.
Getting shot by the fireballs moves you fast enough that odd collision things happen. It also doesn't halt your attack like getting hit by enemies does.
I got my controls to freeze completely during the cave cutscene. Basically, the text boxes appeared, but after I closed them, no buttons worked (Not even enter). Maybe I jumped too far? I'll investigate more how I did this.
I expected going back in the menu to be on an action key (A, E or R) instead of enter.
I assume the text is still placeholder, so I won't comment much on it. But part of the old man's intro text is still in French. (The stuff he says before he opens up shop so you can buy from him) Depending on how the game is being translated, that might be important to know.
Apologies if I'm being too crazy with this. I'm trying to be tactful, and I do understand it's a beta. But I feel it's a disservice to find a glitch, and not tell you, even if it's probably known.