I'm a little biased because I really like typing games, but I really liked the concept behind this game! The idea is super cool and I enjoyed playing it. The game has pretty minimal visuals and audio, but they're still cohesive and fits the general vibe of the game.  

I still have some criticisms though. The game ramps up in difficulty really quickly though with 2 pairs of swapped letters, and I think that difficulty felt unfair because it's hard to tell which 2 letters were swapped at a glance. I think that if the different pairs of letters were diferent colors, it would feel a little less frustrating. 

Good work, and good luck on your guys' future projects!