Not another Jigidi puzzle [Solutions posted]

Instead, I present the laziest yet largest puzzle giveaway I've made. Each set of ten questions allows you entry to a shared group of fifteen great games, while also giving you the links for four still-pretty-good games unique to that set of questions. Most require level one, but there are several games not requiring contribution. Many of these games have been bundled by now, but none are what some call 'bundle trash'. Hopefully FTL, AC III, Bastion, Watch Dogs, Castle of Illusion, Endless Space, Mirror's Edge and others interest you enough!

If you know/can remember/can figure out why these questions are lazy despite there being forty of them, then lucky you! However, please keep that knowledge to yourself.

Set A
Set B
Set C
Set D

To console non-participants, KCPW6 wants to help. Giveaways end 7AM UTC 16/4 (ended).

Please do not share answers or links. In familial circumstances, limiting entries to 1 per giveaway per household is fine.

Solutions below
Set A
Set B
Set C
Set D

For the curious, all the questions were taken from an SG chat trivia session you can compare yourself to here, where this was the prize. I re-used all my questions, with some small optimisations. All the old trivia logs are linked here.

One lucky duck managed to win a whole third of the prizes! Some crazy odds there, or SG being weird on giveaways that end at the same time :o

Some minor explanations of my expectations re:
B2 - Aus. Robin Hood = Ned Kelly, 'their kind' = bushranger, so 'longest surviving bushranger' in google gives captain thunderbolt. Also mentioned as such on Wikipedia page for bushrangers.
C5 - There were many failed social media services back then, but out of the 'household brands, I was expecting recognition for MSN/Windows Live Messenger to be right up there, which would lead to either googling 'msn+migrated+wordpress' or the wiki page for discontinued Windows Live services and ctrl+f blog.

If you have any questions/corrections, please post below. Above all, have fun :)