If these reviews are accurate then it sounds like Unit 13's set a decent benchmark for military shooters on the Vita. Crucially, they seems to have got the controls and mechanics right, giving prospective devs something to look at.
So far the only negative stuff is the lack of story really.
Unsure why that is an issue, the gameplay is what matters in Unit 13 IMO.
Yes we can buy games like Uncharted that are story driven and are great, but when I'm running around shooting things do I need a story or just need to eliminate some more bad guys?