Keen is tricky because it has many meanings in English. There’s no way of knowing which of them are valid in American English without looking them all up in a dictionary.
The pun is that the name of the organization is The Keen Company, and the ad says, “Keen to see something amazing?” Saying you’re “keen to” do something is the particular use of “keen” that has caught on recently in American English.
Google Ngram and I beg to differ. “Keen to” is a phrase that was popular in the U.S. in the first half of the 20th century, peaking around 1920. I recall it from “old” movies of the 1930s and 1940s. Its use began to pick up again around 1980 in both AmE & BrE, and from what I can tell, it’s always been more popular in the U.S. than in the U.K.
notoneoffbritishisms.com 
There was an old DOS game series by iD/Apogee called “Commander Keen”. I don’t know if they intended it as a pun or not.
I suppose the non-pun version would be, “Keen to /present/ something amazing.”
Sorry, but what is the pun? As a Brit who has always had keen as part of my lexicon, I need some context here.
Keen is tricky because it has many meanings in English. There’s no way of knowing which of them are valid in American English without looking them all up in a dictionary.
The pun is that the name of the organization is The Keen Company, and the ad says, “Keen to see something amazing?” Saying you’re “keen to” do something is the particular use of “keen” that has caught on recently in American English.
Google Ngram and I beg to differ. “Keen to” is a phrase that was popular in the U.S. in the first half of the 20th century, peaking around 1920. I recall it from “old” movies of the 1930s and 1940s. Its use began to pick up again around 1980 in both AmE & BrE, and from what I can tell, it’s always been more popular in the U.S. than in the U.K.
BTW, I got the pun from the outset.
And there’s a usage of ‘keen’ equivalent to ‘cool’.