Great news or greatest news ever?! The reason I got hooked on Let's Tap was due to all the awesome music in the game, theme song included. Now, SEGA has confirmed that the Japanese soundtrack will indeed be kept for the North American release. I'm sure it'll be the same for Europe and Australia.

Link

UPDATE: Just wanted to note that I also got a confirmation from Sega via email about the inclusion of the entire Japanese soundtrack for Let's Tap!! —cortjezter