This OVA is a 13 minute-long promo for the game Zero Escape: Virtue's Last Reward. So unless (a) you are planning to play this game, (b) you are finished with VLR and are searching for related material, or (c) you are merely curious about this game, there's honestly no need for you to watch this. On a side note, if you are planning to play VLR, then don't worry, there are no spoilers in this OVA. It's mostly just an introduction to the game (the characters, how it works, etc.). In fact, I'd say it would be good if you watch this to get you started. Overall,it was good for what it was made for—and that is, promoting the game. I should add that if you're planning on playing VLR, I recommend you play 999 first. This is the sequel, so it only makes sense to play the first one before you play its sequel. The story will make a lot more sense that way too.