What else is left to offer for Vita? That's a serious question, I'm a Vita owner and haven't touched the thing for a solid year or something.
While I agree that the well is running dry on older titles that can be offered, the Vita has gotten great games all year.
Maybe you should pay attention, or broaden your tastes, because these are some of the more notable releases of the last twelve months:
Darkest Dungeon (which just released yesterday and is an awesome port)
Digimon Cybersleuth
Risk of Rain
Crypt of the Necrodancer
Hitman Go Definitive Edition
Earth Defense Force 2
Senran Kagura Estival Versus
Legend of Heroes Trails of Cold Steel 1 & 2
Skullgirls 2nd Encore
Axiom Verge
Lego Star Wars TFA
Stranger of Sword City
Severed
The Last Blade 2
Downwell
Nuclear Throne
XCOM Enemy Within Plus
Civilization Revolution 2 Plus
Atelier Sophie
Volume
Assassin's Creed Chronicles
Odin Sphere Leiftraser
Oddworld Abe's Odyssey
Steamworld Heist
Alone With You
God Eater Resurrection
Ray Gigant
Adventures of Mana
Grand Kingdom
Zero Escape 3
Shiren the Wanderer 5
Gal*Gun
Hatsune Miki Project Diva X
Psycho Pass Mandatory Happiness
Superbeat: Xonic
Dengeki Bunko Fighting Climax
Organ Trail Director's Cut
Super Meat Boy
Lot's of great games in there and something for everyone.