Both versions of Nuts & Milk involve the player moving through various levels while collecting an assortment of fruit scattered throughout each one. By gathering all the fruit on a particular screen, the player will gain access to a previously unopened house door containing Milk's fiancée. When the player makes contact with the female blob, they are advanced to the next level to start the process anew. Movement through these levels is accomplished by using the directional pad or keyboard to move Milk across the stage while avoiding pitfalls and other obstacles, most notably the character's rival, Nuts. If contact is made at any time during game play with Nuts or other harmful objects such as miniature blimps, the player will lose a life and have to repeat the current level, with all fruit reset back to their initial positions. Once all three of Milk's lives are lost in this fashion, the game ends.
Source: Wikipedia, "Nuts & Milk", available under the CC-BY-SA License.