n-dimensional sequential move puzzles
... that the 120-cell 4-dimensional puzzle is one of several n-dimensional sequential move puzzles that have been implemented as virtual puzzles but have never been solved?
... that the <a href="./120-cell" id="mwAzc" rel="mw:WikiLink" title="120-cell">120-cell</a> 4-dimensional puzzle <i id="mwAzg">(pictured)</i> is one of several <b id="mwAzk"><a class="mw-redirect" href="./N-dimensional_sequential_move_puzzles" id="mwAzo" rel="mw:WikiLink" title="N-dimensional sequential move puzzles">n-dimensional sequential move puzzles</a></b> that have been implemented as virtual puzzles but have never been solved?