Glitch is very good about keyboard escapes for menus, but it lacks a cancel shortcut for actions. I have three scenarios explaining why I think using the escape key to cancel actions would improve the game:
1. A new player finds a rock on the right end of the screen. He starts to mine, but notices the action will result in the pooped status, likely resulting in death! He tries to cancel, but (sad sadness!) he was standing so close to the right of the screen that the little 'x' after the bubble text can't be clicked! This kills the glitch.
2. A player is in a race against the clock to harvest the trees on her yard before the new day! In her haste, she accidentally chooses 'pet' instead of 'harvest'! In the time in takes her to move her hand from the keyboard to the mouse, move the cursor over the tiny 'x' and click, the new day has arrived! The glitch bemoans the lack of a keyboard escape option!
3. A player wants to make a FHSP and an EHSP. He starts making the FHSP but soon realizes he won't have enough sparkly element left to make the better EHSP. He wants to cancel, but alas! The window chides 'let it finish!' when he tries to cancel the operation. Back to the salt mines for you, little glitch!
In short, I love keyboard shortcuts and I hope I've made a compelling case!