Duck Rush is a challenge mode that only appears in Where's My Water? 2. Duck Rush levels automatically scroll up or down while the player completes the level. Duck Rush levels contain six ducks, and come in Swampy, Allie or Cranky levels. The player must keep the water/ purple water/ steam on screen at all times otherwise the level fails. The respective fluid must also enter the final drain to complete the level.
- Challenges (e.g. Avoid It! etc.) are absent in Duck Rush levels.
- Before starting a level, both Allie and Cranky face the player while Swampy faces the pipe.
- Swampy has 15 Duck Rush levels while Allie has 6 and Cranky has 5.
- Lists of levels that are Duck Rush levels: 2, 9, 13, 19, 25, 28, 34, 39, 43, 50, 54, 60, 63, 69, 72, 78, 84, 90, 98, 104, 110, 114, 119, 124, 128, 133
- At the start of every Duck Rush level, Swampy will twist the wheel, Allie will pull a chain and Cranky will punch the pipe. If the player taps them again, Swampy and Allie will repeat those actions while Cranky will point down.
- When you fail a Duck Rush level, Swampy looks at the player with disappointment, Allie sighs and Cranky growls at the player.
- Depending on a device the player uses (Apple or Android), Cranky talks by saying "Raaag! Rrrrmmm! Ha ha ha ha!" or simply "Rrrrmmm! Ha ha ha ha!" when punching a pipe at the start of his level.