Here are the Free games joining PlayStation Plus EU and US In September 2014
All the free games for US and EU are the same in September.
Games Joining PlayStation Plus In September
PS4
Velocity 2X ( PS Vita Cross-Buy )
Sportsfriends
PS3
PlayStation All-Stars Battle Royale ( PS Vita Cross-Buy )
Hoard
PS Vita
TxK
Joe Danger
For PlayStation Plus EU, these games will join on 3rd of September.
Games Leaving PlayStation Plus EU on the 3rd of September
PS4
Road Not Taken
Fez
PS3
Crysis 3
Proteus ( Cross-Buy With Vita )
PS Vita
Lego Harry Potter: Years 5-7
Metrico