So SteamWorld Dig came out this week, and it's a fun little Western-themed Metroidvania in which everyone is a robot. The twist is that you create your own pathways by digging through the ground, uncovering various gems that you sell to buy upgrades while also finding new abilities as you dig deeper and deeper into the ground.
Really tight gameplay (you can even wallkick Mega Man X style), great 2D graphics, highly HIGHLY recommended.
It's only $9 on the eShop. I got it with that $30 credit from getting SMTIV.
oh also, original DK is coming to 3DS VC on the 15th, Wario Land 3 is hitting on the 29th, Tecmo Bowl is kicking off next month, and both 3DS and Wii U will get SMB3 later this year.