They're TOO good. Seriously, google a list of reviews of PSN exclusive games and you'll be hard pressed to find a game that scored below 8/10 among the bunch. It's a nightmare getting to all these critically acclaimed games but luckily PS Plus helps with this as most of the games they give free are PSN exclusives. Rain will just be another title to add to the already very long list I guess.
Could you recommend some since I seem to have missed out on some and the storefront on PSN is f**king nightmare to navigate for stuff like this? I currently have Journey, Flower and Machinarium (though that isn't a exclusive).
There is a section in the store for top PSN/most popular titles.
I would recommend on top of what you have said:
Papo & Yo
Sound & Shapes
Okami HD (supposed to be good, haven't played it but waiting for PS+ update)
Infamous: Festival of blood (its a standalone game you don't need infamous 2 to play it)
The last guy
Rag doll Kung-fu (is hilarious for MP)
Theres loads, depends what you're after. Best just to google ithttp://uk.ign.com/articles/2013/02/28/i ... mes?page=5