Well, hard to say.
Date a live is by itself average anime for many people. I'm not saying you wouldn't like it. As for me I'm a huge fan of Date a live series so when I heard that this anime has a game I immediately bought it. This game offers so much interactions with almost everyone you know from the anime. Good music, gorgeous backgrounds and of course, amazing story. Currently there are 3 story lines, each one of them is offering a new experience. Characters are literally same as they were in anime, maybe even more funnier (Natsumi and Mayuri aren't still there though :/)

For someone who hasn't seen the anime, this game could be boring and you won't probably play it to the end. If you are looking for a dating simulator then I'll probably disappoint you, because this is not a typical dating sim. And again, If you haven't seen the anime you wouldn't get the humor and you probably wouldn't like the characters.

My conclusion is this:
If you've seen the anime and you liked it, then buy it (maybe in some sale, the price is too high if you ask me).
If you've not seen the anime then I can reccomend it to you as a good visual novel game. And again I can't guarantee you would like it.