Once you collect the clover you can use it repeatedly. It has a cooldown. You can use it again (Q or E) when the box around the clover icon in the upper right corner gets white again. (mental note: one more thing to better communicate in-game, rather then via hints in the description, we hear you!)
I appreciate the length of your feedback! Very cool and very helpful, thanks! pixel-fabian is the programmer, so it is his domain to answer your question. :) And please reload the game page rather than clicking restart for more randomized variety of monster sprites :-)