U.F.O ending is on "Grow Island."
Grow Valley has the underground alternate ending:
1. Magnifying glass
2. Gear
3. Heart
4. Computer Chip
5. Compass (or is it a surveyor's transit?)
6. Pickaxe
7. Beaker
Chat with our AI personalities
There is no secret ending. (the 3 games that do are Grow version 3, Grow Island, and Grow Valley)
This could refer to the game "Grow Cube" (see related question).
This may refer to "Grow Version 3" aka "Grow planet" or some other Grow game. (see related questions)
Shield Soldier Gate Tower
There is only one, updated version of Grow Cube. (see the related questions below)