Ask if you can see a picture of it, if it matches the bottom one colored white with the circular start, select, and ps buttons, it's LCD, if it matches the top one with the oval buttons then it's OLED.

Also from the list of games that I listed and others I didn't that are multiplayer.

Wipeout 2048 is multiplayer through both adhoc and online. If you want to play online it requires an online pass so I'd recommend to buy new.

Unit 13 is multiplayer only through online so you're required to have an online pass. This game is an excellent score based third person stealth/shooter game. It's designed for single player but all missions can be played multiplayer.

Soul Sacrifice. I don't know if it has a online pass because I played the digital version(it's a Sony game though so I'm guaranteeing the physical version requires an onlinei pass.) I played online so I don't know if it has adhoc as well. The story mode is single player only, it has a lot of additional missions that can be completed multiplayer.

LBP Vita. It requires an online pass and I don't think can be played adhoc.

Dragon's Crown. I've only played same screen co op on the PS3 version, so I don't know if the Vita version is online only or adhoc.

Gundam Breaker. I've only played the PS3 version has no local co op so the Vita version may be online only.

Ragnarok Odyssey Ace. There's no reason to get the non ace version as it has less content. This game has both online multiplayer and adhoc multiplayer.

Earth Defense Force 2017 and EDF2. I've played EDF2017 and I know it has online multiplayer, not sure if it has adhoc.

Playstation All Stars. I've never played the Vita version of Playstation All Stars, so I don't know if multiplayer can be played through adhoc or if it's like Unit 13 and is online only. It also requires an online pass. Playstation All Stars is an easy to learn fighting game but it's actually got a lot of depth to it. One of the best fighting games I've ever played, the only issue is that on both high and low level play their are some unbalanced characters. Good Cole is a crappy character when you don't know how to use him, but he's the best character if you know what you're doing.

If Sony actually put some effort into getting some memorable Playstation characters and didn't send Playstation All Stars off to die as nothing more than advertising for some of the games coming out with nothing more than a few classic characters, they would have had an amazing franchise on their hands. Nintendo does what Sony don't though it seems, because while Cloud would have been a perfect fit for Playstation All Stars, among many other characters fans begged for, Nintendo who has never had Cloud on any of their systems except for spnoff games like Kingdom Hearts, Theatrhythm, Final Fantasy Explorers, he's a big part of Playstation, being on the first Final Fantasy the Playstation has ever had, a game partially funded by Sony themselves, being featured in Dirge of Cerberus Final Fantasy 7, a sequel with Vincent as the playable lead character, Ehrgeiz one of the included characters, Dissidia(the Final Fantasy fighting game,) and then not a Playstation game, but Sony Pictures also published Final Fantasy 7 Advent Children. Characters like Cloud, Snake, Lara, etc, characters that people actually wanted would have put sales into the multi millions, because then it would have been a true celebration of Playstation.