I'm a lifelong fan of grid-style logic puzzles, and this is basically the same idea. I prefer the grids, but that doesn't keep me from enjoying it.

Pros:
* automatic fill / removal when you narrow down a piece (autosolve)
* nice music
* the ability to discard a clue you're done with (and get it back if you discard by accident)
* the all clues or one clue at a time options
* customizable puzzles
* ability to change confirm / remove controls

Cons:
* it tells you immediately if you make a mistake (seriously, I hate this)
* no undo
* the default short & long click controls resulted in a lot of accidental mistakes (but see above, you can change them)
* goofy justifications for clues that don't make sense (only one person is qualified to use duct tape???)
* similar-looking items are easy to confuse (blue butterflies, red trains, etc)

I think the ideal solution to the immediate feedback and no undo problems, while keeping an option for autosolve, would be to put autosolve on a button.