Mark Sweep's puzzles

While I really enjoy the logic this variant has to offer, it is sometimes a pain how restricted a grid already is by placing just a few circles.  Rules Draw a non-intersecting loop through the centers of some cells that passes through every circle. The loop must turn on black circles and travel straight through the cells on either side. The loop must go straight through white circles, and turn in at least one of the cells on either side. No two consecutive straight line segments may be the same length. Solve online

All these stairs would make for quite the bumpy road. Rules Draw a non-intersecting loop through the centers of some cells which passes through each region exactly once. A number in a region represents how many cells in the region are visited by the loop. Orthogonally adjacent cells across a region border may not both be unused. Solve online

Here is a Heyawake (technically Heyawacky) themed as the sudoku variant Windoku. The break-in might be a bit tricky to find, but should fall apart smoothly afterwards.  Rules Shade some cells so that no two shaded cells are orthogonally adjacent and the remaining unshaded cells form one orthogonally connected area. Numbered regions must contain the indicated amount of shaded cells. A line of consecutive unshaded cells may not cross more than one bold border. Solve online