Attack of the Friday Monsters, Liberation Maiden, and Fairune.
AOTFM is a cute little adventure game, almost point & click like. It's relaxing to explore the town, talk to characters, and uncover the story at a slow pace. It's nothing mind blowing, but it's enjoyable and cute.
Liberation Maiden took me by surprise. It's a blast, reminds me a ton of Kid Icarus Uprising, which is one of my favorites on the 3DS. It's fast, stylish, and just cool. It can be challenging too, I like it a lot. Especially playing it in sync with AotFM, the two just pair well due to their stark differences in pace.
Finally, Fairune also took me by surprise. It's nothing ground breaking, but it's a very fun adventure game in vein of the classic Zeldas. You have a map to explore and are given items that you have to figure out what to do with. Combat is as basic as can be, but fun as you progress through the game. It's charming and fun, and I'm actually a bit stumped as what to do right now. I'd recommend it to any Zelda fan. Plus, it's only like $2 right now. A steal.
Overall, the Level-5 sale really took me by surprise with how great these games are. Fairune as well which is unrelated to the other two, but just a cheap, fun game. I'd highly recommend picking up at least one or two of these games. There's so much variety in the collection, you're bound to find something you like.