Level 30 is the level. Find the cave in the ceiling to the right of the rabbits' village underground, go up there, stand in front of the level and press down. This also activates the water pumps and give u learning skill.
I must say the ending sucks. The artwork is good but unprofessional and the music contradicts with the outcome. Anyway, if your having trouble beating it and ur almost done, max out all ur stats then stand in front of the computer and press down (P.S. if u have full stats + double jump u can enter the lab by jumping up from the bottom at the cave entrance below. Thats what i did coming back to this game.) anyway, wouldn't play it again unless a badge were to become available.