Cool game. Fun stuff to note: If you pick up an extra life in a level, you can duplicate it. Even with the Power of Permanence, they won't carry over, but they can be used in that level as 6 1-ups, and any duplicated 1-ups don't count towards your max, so you can still pick up 1-ups until you would have hit 6 pre-dupe. Interestingly, if you lose all 6 1-ups, any excess that were dupes are actually counted as negative for the remainder of the level. So if I have 4 on level 4 from picking up that one, I drag the 1st to the 5th slot, and the 2nd to the 6th slot. I now have 6 1 ups until I beat the level or switch it. If I elect to use all 6 instead, then reset the level, and then pick up the 1-up again, I don't get any 1-ups until I wrap back to 0 1-ups first.
Also, the glitch that freezes the game happens if you are holding the 1-up that gets used to revive you when the counter hits 0.