So a recap on ugolegend94's clues and other such things...
--You must use the mouse and keyboard to get the medals.
--Keeper of Secrets description: "Use all your skills to get this medal, you'll need patience and calm, NOTE: if you press tab or cheats you can not unlock this medal forever!"
--The Keeper of Secrets medal is a hidden button.
--The previous medal from Newgrounds Medals Ext was indeed a hidden button, but it showed a picture of the medal icon if you rolled over it with your mouse. The same is true for Red Eye in Pico's Musical experience, although it's only slightly more complicated in terms of finding it.
--It is found in levels 2 or 3.
--It is much more difficult to get than Sailor Moon. Subjective, possibly.
--Pressing tab does not reveal the Pervert secret medal. In fact, tab seems to break from that point onwards, at least until you restart the game.
--On a related note about the Pervert secret medal, it is no longer available after an event. For those with the medal, they'll know what I'm talking about if they check for its availability without actually getting it.
--Sailor Moon description: "The moonlight lights up the galaxy"
--It's been inferred by NewSoul's medal order that the screen this medal is obtained from is the entrance to the NG office. Confirmed by ugolegend94.
--Do no harass NewSoul for how to get Sailor Moon. I thought it wouldn't be fair to her just because she's your GF, so I didn't PM her. For those that did, SHAME ON YOU!!
--ugolegend94 claims to have seeded clues on how to get the medal for a long time. Perhaps as early as his first mentioning of this game? Work on the game has started since the last quarter of 2010 IIRC.
--"Here is the final clue, <find the face of sailor moon and you'll find the medal>"
So right off the bat, I'm still clueless about how to get Sailor Moon. I will need to do some diving in this thread to see what I can turn up, but right now I don't have the time.
As for Keeper of Secrets, possibly the least hair-ripping solution I can think of is to get a perfect on level 3 and look for the hidden button at some point. Other than that... sky's the limit =/