That ad's been on there forever. I thought it was funny, too. I actually took a screenshot of it as well a while ago, thinking about posting it here. But I decided not to
google ads are random...stupid.
u could (just for a laugh) enter "slaves" in google and on the right side will prolly pop up something like "get cheap slaves now! only xx $!"
same with ebay, whenever u search something on google ebay seems to have it.
From what I understand visiting the site, this could be a download service offering more than 800 million games online... 800 millions?
Anyway you would probably end up with the demo version of LFS. I wouldn't say it's illegal if you pay for a (needless) download service, but both the advertisement and the homepage are dodgy since there's no significant additional info about the offer. You're left in the dark until you submit your email address (which, for the record, I won't do) .
If it was S2, it would just be misleading from what I understand, not false. Whether misleading advertising is illegal or not varies from Country to Country.
Edit: for instance such advertising in Italy would be considered illegal because it's considered dolus malus and not dolus bonus: you can magnificate the qualities of your product, but you cannot do it with a malign intent. The intent of the advertiser is clearly to mislead, so it would considered malign.