I have run into a very annoying bug. Sometimes when I press 'down'(the 's' key) once, the game acts as if I were holding down the key and several turns pass before I realize what is happening. This has killed me on more than one occasion. I haven't noticed this happening with any other directions.
The experience increases are definitely outpacing the energy increases. So the more I play, the LONGER it takes before I can play again, contrary to the developer's response.
Suggestion: Keep the current difficulty as "Copy Cat"; a higher difficulty--all 99%s--"Forgery"; and maybe a lower difficulty/speed trial 60% "Impressions". Cool game!