I wonder if the delay is intentional so users start paying and want to finish. If they saw ads, they may immediately leave. Also ads can slow down a website load times so the delay may be for SEO.

It's intentional. The first 5 games are ad-free. Most of the ad-revenue are from people who stick, so I kind of try to give people the best experience the first 5 games.

Isn't that kind of like penalizing your regular - repeat customers?

Except they are not his "customers", they are his product :)