The question is: Why?

One important key to a great review is asking the question: why should the reader watch? 50 words isn't much but it's possible, sometimes with a bit of tweaking, to show a little of all of these:

• how well it was made
• who stars in it and how good they are
• the story line (introduction and outline, but no spoilers)
• the emotion it stirs

Combine all four and you've done it!