Cute little game!
I liked the visual style, helping the Ai on a computer. Although, were probably just getting a virus getting it past this many firewalls...
It can be hard at first to know when to press the buttons, since all we are given is "when I am close to". Which led my first few tries just finding out how close "close" is. This can be a hard thing to develop for, since once you've played it for long enough you don't see this as an issue since you then know the timing.
I found some of the strings to be more fun than others, (while I assume they are randomly generated), ones like Up, Right, Down are fun since then you can "slide" down the arrows.
I can see more being added to this, like longer strings to type out (with more time to press them) and maybe some ways to change up the idea. Like doing a small sequence, then having to remember it and do it in reverse. Becoming a game like One Finger Death Punch.
I found most of my errors were just when my brain decided to stop focusing, and just get me out of sync. I think having the order be told through visuals would help this, since then you don't have to process the words.
Although I did find out that you can just spam all of the arrows, and you will still get it correct... maybe have some implementation to make sure the sequence is pressed in the correct order.
Nice job!