It was a short while since the last update. Stage 3-1 does take quite a bit of effort to create - which shouldn't be surprising considering it has a whole new major mechanic to it that even I have to learn, both from the player's and level designer's standpoints. That being said, at the very least the maintower part of the stage is complete (though even major changes are still possible), so I have decided to push it out in form of a beta.
To access the beta, go to the game's settings on Steam, then choose the beta branch in the Game Versions & Betas tab. Please be aware that because the stage is not yet complete, savestates on this stage may become broken with the future updates. If this is a problem for you, please consider staying on the default branch and wait for the moment where 3-1 is complete.
The maintower part of the Stage 3-1 is available to play.
Fixed the bug that allowed you to enter not yet unlocked stages (don't worry, the unlock all option still exists if you want to use it!)
Fixed a wonky doubleclick behaviour in the main menu.
Increased default width and height of the screen by 2 pixels each to make it harder for accidental resizes to cause unexpected effects when "Force pixel perfect scaling" option is used.