Yup, Mangagamer’s just released an all ages version of Kirakira today. This makes me curious about 2 things: how many more games they’re planning to re-lease and which font it uses. On the other hand, they’re releasing Higurashi Meakashi-hen soon, though it’s only one chapter by itself (while still charging 20 euros). This smells suspiciously like a cash cow maneuver. Maybe they’re actually doing badly financially? Is that why they’re crap like “Cosplay Alien” ? (UGH, I feel annoyed just typing that out)
Calamitous Intent 
I don’t … recall an all ages kira kira in general. I think there’s a console port but this seems to simply be the same game with the 18+ CGs taken out. I could understand if it was like a console port where there may be additions, different voices, or whatnot. Maybe its font like you said.
If there was already an all ages of Kira Kira in Japanese then this kind of makes sense, but even then, I don’t really see the advantage of this because you’d have to be like (or should be) 18+ to view the mangagamer site in the first place.
Maybe its all ages version allows it to be presentable in more locations/sites.
There never was an all ages Kirakira in Japan. MG said, and I quote “This product has been modified fom the adult version of “Kira Kira” by removing scenes that would effect its age rating. Please be aware that there is no additions to the gameplay.”
You don’t need to be over 18 because they opened their all-ages section a while ago, and typing in http://www.mangagamer.com directs you directly to the all ages section.
I don’t think it’s anything more than trying to get more customers.
Regarding MangaGamer, they’ve yet to turn a profit. The only reason they’re so prolific is that the company is directly funded by a consortium of Japanese developers (CIRCUS, OVERDRIVE, Nexton, Navel, etc.) who already have a reliable financial base and who’re eager to crack the overseas market. In the meantime, they can afford to take a loss on the English-language project.
As for Higurashi, I’d suspect that the game didn’t sell so well, so to justify continuation, they’re maximizing prices for those still willing to buy.