It's actually remarkably similar now to what it was really early on. There's a lot more refinement and polish now.

Here's a video from about 2 weeks into the project (it was codenamed Fractured at that time):

https://www.youtube.com/watch?v=BeMt9UJIPS0

One key mechanic in the game now that isn't in this video is the auto-panning after the user makes a word

(there's a bunch of other stuff too, like the timing mechanism, size of tiles, size of game grid, etc.., but that's more gameplay rather than mechanics)