Frontier Days and Mercenary Saga 2 for the 3DS. I actually bought Frontier Days a while back, when I used some coins and got a discount for it. Mercenary Saga 2 also had a sell a few days back, and I bought it then.
Frontier Days is... think, Age of Empires, without the war. It's actually made by Arc Systems, and by clearing certain tasks/achievements, you unlock a couple of images involving their famous fighter game.
Mercenary Saga 2 is more or less the same thing as Mercenary Saga 3. (Duh?) As it came before 3, the UI actually feels a bit less polished. But it'll do. Cheap too.
Oh, and BTW, the sequel/expansion of Frontier Days is going to be available on the Nintendo Switch too! <- Shameless advertisement