Kirby's Return to Dream Land HAL Rooms
Just like in Super Star Ultra, HAL snuck in not just one, but two new HAL Rooms! The first one is much harder to find, as you have to go as far as right as possible on 1-4, then back-track to find a section of ground has lowered. This HAL Room is amazing for granting access to four superb abilities VERY early into the game. The other room is found on 6-5 and isn't as well hidden, but still pretty easy to miss if you don't bother to explore that cranny.
