I don't do detailed reviews anymore (will leave a short one when I'm done) but since you're still around, feedback might not entirely go to waste. it's good stuff (well, it's tim, same as 30 years ago) but:

- an alternative control method (click to pick up, click to place) would be nice on top of hold & drag for accessibility reasons

- another volume slider for sfx, now there's only overall and music

- the goal window with the description should be bigger to fit all text, no need for a scroll bar for 1 or 2 lines

- newly-added puzzle packs should go to the end of level select, keeping the tutorial and easy stuff on top

- opening a pack on level select should jump to the page with the first unsolved or last played level, not always page 1 (dealer's choice, I'd go with the former, as it tends to cover the latter)

- level numbers would be good, both on level select and while playing (e.g. boom! -> #17: boom!)

- level pack progress should also be shown inside a level pack and while playing, not just on level pack select (so instead of 'tutorial puzzles' it should say 'tutorial puzzles (14/54)')

- due to this I didn't realize I finished the tutorial levels, as even after the last one it kept loading the next level in the next pack instead of informing me the current pack is done

- right click could remove items, not just left click to select, left click on bin

- clicking an object anywhere (not just the connection points) should select it (and remove if implemented)

- user-placed objects should be marked somehow to make it clear (without clicking around) what's there to fiddle with and what's pre-placed and fixed

- the help screen for an object should be accessible from the inventory, not only after placing the thing on the level (right click or mouse wheel click)

- window size and position should be kept when switching back and forth between full screen and also between sessions (quitting in windowed mode starts the game in a window next time at least)

- might be my really outdated gpu drivers (then again, the game is years old too) but switching to a window messes up my desktop, leaving parts of the game where they shouldn't be anymore

- quitting the game should be possible from the settings, not just by going back to the main menu via multiple clicks (I'm aware of alt+f4, not the point)

- the main menu itself is really annoying with everything making a sound in the background

- the help button in the main menu bringing up the steam overlay and a youtube video is really lazy, so how about an encyclopedia of sorts with all the objects and their descriptions? or it could just be a pre-recorded in-game demonstration instead of streaming video outside the game