On Kongregate, the SWiTCH vs. Evil Dog one is impossible, because of numerous lag that foil any attempts on that tremolo passage towards the end. (where you rapidly press the up arrow)
The bugs are really ridiculous sometimes. You can actually play that free black card without discarding anything if it's the only thing on your hand atm. Also Enforced Silence is really screwed too if an opponent plays it on you.