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This crossword has standard clues. The twist is that some or all of the answers must be written backwards (or upwards) in the grid.
Puzzles in which the solver knows which answers must read backwards (all the Across answers, for instance) offer little in the way of extra challenge. Visualising reversed answers in the grid is an unfamiliar task, but not a particularly taxing one.
A second version of the puzzle gives no information on the quantity or location of the reversed answers. This does add a new element to the solving, since known answers can't immediately be put in the grid without reference to intersecting answers.
From a compiler's perspective, the thing to watch for is ambiguity in the direction of answers in the grid. A word such as ENTITLE might be intersected in the grid on letters 1,3,4,5 and 7, and still fit in the grid forwards or backwards.
A standard crossword but with a twist — some or perhaps all of the Across answers are to be entered backwards in the grid. For example, if the answer to 9 Across was LOVE, you would write EVOL. Enter the Down answers as normal.