Laranjashtear, there actually is a meter for the invincible, it appears under you when you get it. its really small, and i got over a dozen invincibility power ups before i realized it was there, but its there.
actually, im focusing on rating games by the badges, and i thought this hard badge was annoying so i got annoyed, but judging this as a game without paying attention to the hard badge, its a 5/5.
i know this will get rated down but this doesn't really seem like jmtb02's style of game, and i didn't like it quite as much as his others. still a good game, but i'd rather be playing this is the only level or achievement unlocked.
i wouldnt say that the hard is harder than the impossible, considering you can let lots of blocks fall and not mess you up for the hard badge, but they're both really hard.
nvm, i finally found it. a better description of where it is is: it is in skim the sky. when you are entering it from the left, go down the big cliff and stay against it. there will be a wall for you to destroy and it will lead you into the room with the 4th song.
 "Robot Dinosaurs That Shoot Beams When They Roar"){kind=icon}
 "Amberial: Nebulosa Realms"){kind=icon}
 "Amberial"){kind=icon}
 "colourPod"){kind=icon}
 "Continuity"){kind=icon}
 "The Company of Myself"){kind=icon}
 "GlueFO 2.0"){kind=icon}
 "Vector Runner"){kind=icon}
 "Luminara"){kind=icon}
 "Amorphous+"){kind=icon}
 "99 Bricks"){kind=icon}
 "Mr. Bounce"){kind=icon}
 "Legend of Kalevala"){kind=icon}
 "Impasse"){kind=icon}