I made up a simple solitaire game while I was just idly shuffling a Heckadeck. It doesn't take up much table space and it's easy enough to play.
The Deal: Take the 128 "simple" cards (16 each in 8 suits) and shuffle them. The other cards will not be used this game. Deal out 7 cards, face up, in a row, and place the rest of the deck face down.
The Play: Pick up any card or stack of cards, and drop it on top of a card of a matching suit or value. Then turn up a card from the deck to fill the empty space. Continue until there are no moves left.
Scoring: You score 1 point for every non-empty pile remaining, plus 1 point for every card remaining in the deck. Thus a perfect score is 1, if you exhaust the deck but have no moves remaining then your score is 7, and if you run out of moves with three cards left in the deck then your score is 10.