Solitaire

As the description says, you'll need to win a game of Klondike without ever pressing to undo a move. This can be done on any difficulty, so I highly recommend playing the single card version instead of the three card version. The single card version is much easier and very simple to win.

To win Klondike without undoing, all you need to focus on is uncovering all of the cards across the board. The draw pile up top should only be used to help you uncover cards on the board, and uncovering those cards should always be priority. This is why the single card draw pile is so much easier - you don't need to worry about uncovering cards in the draw pile like you would in the three card version.

You have to win 5 games anyway, and this is by far the easiest game mode, so there isn't much planning or anything to think about here. Make moves whenever possible to uncovered flipped cards. The only real planning is when you have a blank spot on the board where only a King can go. If you have a red and a black King available in the draw pile, check your cards on the board and use whichever King will help you flip another card. If you have a black Queen or red Jack or black 10, then opt for the red King, and vice versa if you have the opposite suits.

The only time you really have to make a decision is if you have two red or two black cards to choose between moving on your board - for example, the Queen of hearts and the Queen of diamonds and you've got a single black King. There isn't much you can do in these situations other than guess and hope to get lucky. This only happened to me in one out of my five games though, so within your five wins you should easily be able to finish one without undoing.