Sogi-Ya: since you mentioned that this is about dragon's dogma, I am assuming the issue is the expiring subscription is in a European PSN account while your main
is a US account.

.... since the US ps+ hasn't gotten that game.

the answer is no, you can not keep playing the game if the subscription it is tied to expires. once the subscription expires PSN shuts off that game code, regardless of if the ps3 it is installed on has another account with an active subscription on it.

likewise, PS+ memberships are not cross compatible and you will need separate subscriptions if you want access to the game lists for each region.

Punished_Snake: They are both EU account :)

Zchinque: The last part there is wrong. If you resubscribe you get access to everything you had downloaded under your previous subscription.

Will I get access to my PlayStation Plus games if I renew my subscription after it has lapsed?

Yes, upon renewal of your subscription you will get access to your PlayStation Plus games. We recommend you take advantage of automatic renewal to ensure you don't miss out.

Source: http://uk.playstation.com/psn/support/ps3/detail/linked285071/item285066/PlayStation-Plus-frequently-asked-questions/