I'm glad to see this is still in development!
It's the content of these words and the act of understanding the stories told by the passengers that's most interesting to me. I don't think it necessarily needs to be difficult or gamey to collect the word fragments.
Generally, I didn't find the click+hold input method to be very intuitive. A number of these could be made more responsive/intuitive by dropping clicking and just using mouse movement/hovering. I'd probably also tweak the string splitting algorithm to make sure a period isn't in a substring by itself; it's a smaller target than the others.
Tap - most intuitive
Charge - took a bit of time to figure out I had to click and hold. just clicking on a word didn't give me any visual feedback I was on the right track. based on the name and previous mechanic, expected this to be mechanic of just hovering the mouse over a string.
Flow - had to both take in that the circle was the goal and that clicking and holding changed the motion of the strings. not very intuitive, particularly since some fragments can get caught by luck of the strings' starting velocity or random motion.
Invaders - again with the click and hold. unless you're planning on making it musical, matching the frequency of the shots to an external background beat, I'd suggest having the catchers fire immediately upon a mouse click. or keeping the extrinsic beat times, but buffering input such that clicking off-beat causes a shot to be fired on the next beat. Or dropping clicks altogether and just continually firing.
Order - I like this one. Promotes engagement with the text.
Sonar - this got confusing. clicking on strings made them flash once, felt like positive reinforcement. gets really confusing if you clump up the strings, causing them to ping at different rates simultaneously. also feels like a lot of work/effort for every single string compared to the other methods. might be streamlined a bit by having a single catcher per round, maybe made visible when it catches the first string in that round.
Choose - funny
Join - I like this one. a bit finicky to actually join the substrings. seems like the sonar one where the dragging mechanics are overeager to drag multiple substrings at once.
Path - invisible paths? really now? I thought at first the goal was to get the two words to meet, which was almost supported by paths that nearly met. seems a bit easy to lose dragging focus if you're moving at the wrong speed.
Sync eh. difficulty determined by the random number generation, involves a lot of mouse movement.