Topic:Write a review of a film you've seen. Convince your audience of your well-reasoned opinion.

Based on the television series characters created by Ross Bagdasarian, the film Alvin and the Chipmunks may have a cheesy, predictable plotline, but the three furry animals make for a wonderful family comedy teaching lessons that audiences of all ages can learn from. “The awesome” Alvin, “the smart” Simon, and chubby, food-loving Theodore entertain as they teach that discipline is important, the glamorous life of the rich and famous isn’t as wonderful as it is usually depicted, and a stable family life is everything.
After the chipmunks’ tree is chopped down in the forest to be used as a Christmas tree in the office of Jett Records, they luckily catch a ride home in a basket full of muffins with Dave Seville, a songwriter whose songs won’t sell. After a long stressful day, discovering the talking chipmunks is no cup of tea for Dave and he immediately throws them out. Later, he hears the trio outside of his window beautifully harmonizing as they sing a song. After discovering the chipmunks can sing he agrees to let them stay in his home (on the conditions that breakfast and television privileges are included) if they perform his songs.
The chipmunks stay at first seems to be a mistake as they trash the house and even ruin Dave’s dinner date with his ex-girlfriend and neighbor Claire. They even freeze up in front of the music producer Ian from Jett Records and Dave is again laughed at and rejected. However, after getting Dave fired from his day job by drawing on his presentation boards, the chipmunks feel they must do something to make up for it as they take matters into their own hands and perform for Ian at his home. The chipmunks become an instant hit and Dave hears the song he has written over the radio at the grocery store.
Dave writes more songs for the chipmunks and provides a family environment for them. He knows that the chipmunks are only kids and shouldn’t be spoiled. He gives them chores, a bedtime, and makes wise decisions to save their money for them. However, their “Uncle Ian” sees the chipmunks as a promise of fortune and since Dave is not for exposing the Chipmunks to an extravagant and stressful lifestyle Ian plots against Dave. At Christmas Dave presents the chipmunks with savings bonds because he knows what is best for them. Uncle Ian on the other hand spoils them with an outrageous amount of toys to play with and even hires a housekeeper to clean for them so they will have more play time. Eventually, by means of sabotage Uncle Ian convinces the chipmunks that Dave is holding them back.
Ian then gives the chipmunks no rules at his home where they arrive to find a room full of toys for the chipmunks to play with. Ian’s carefree lifestyles is appealing to the chipmunks at first, but after they begin strenuous touring and Ian pushes them to record more the chipmunks are exposed to the evil side of both Ian and the fame and fortune lifestyle as they struggle to meet its requirements. The chipmunks are tired of being promoted and miss their stable home life with Dave. They miss being a family unit. All the toys and fame don’t compare to their life with Dave.
Dave misses the chipmunks, too and shows up at a concert to whip them away. However, Ian cages the chipmunks and refuses to let them go with Dave. After escaping from Ian the chipmunks are excited to return to normal life with Dave as a family. They even realize the reasons for many of Dave’s rules while on tour and discover that Dave really was just watching out for them and protecting them through discipline.
The brilliant digitally animated chipmunks create a perfect balance of entertainment and spelling out important values. Accompanied by great music and fun dancing, this film is a must see for all families! The humor will keep you laughing throughout, and the heartfelt message will bring a tear to your eye.

I just don't feel that this is a very strong review, I'm just unsure of what to say to strengthen my opinion.

In the first paragraph you give the theme of the movie... but you do not give any kind of opinion. The rest is more of a summary as opposed to a review.

Was the story appropriate for the age group? Did it have a good point to make? Were the characters well developed? Was the point make successfully?

Here are some grammatical problems in the first paragraph. You have a tendency to write long, convoluted sentences; getting down to "brass-tacks" is not a bad way to write for variety and clarity.

The title needs to either be underlined or in italics;
What is the purpose of the quotes around "The awesome" and "the smart" but not quotes around the description of Theodore?
You have three compound sentences; the punctuation should indicate that.

To strengthen your opinion and create a more compelling review, consider the following tips:

1. Provide specific examples: Instead of general statements like "the film is funny," highlight specific scenes or jokes that made you laugh. For example, mention a particular comedic exchange between the chipmunks or a hilarious misunderstanding that occurred.

2. Discuss character development: Talk about how the characters, including the chipmunks and Dave Seville, evolved throughout the film. Highlight moments where they showed growth, learned important lessons, or developed deeper connections with one another.

3. Analyze the film's message: Dig deeper into the lessons the film teaches. Explain how the film effectively conveys the importance of discipline, family, or the pitfalls of fame and fortune. Provide specific scenes or dialogue that exemplify these themes.

4. Compare the film to similar works: If there are other family comedies or films featuring talking animals that you have seen, make comparisons to highlight what sets Alvin and the Chipmunks apart. Is the humor more clever or the messages more impactful? How do the characters or plot differ from other similar films?

5. Engage with criticisms: Acknowledge any weaknesses or areas where the film fell short, but explain why they did not significantly affect your overall enjoyment. For example, if you found the plot predictable, explain how the charm of the chipmunks and the film's positive messages outweighed any shortcomings in the storyline.

6. Appeal to emotions: Share personal anecdotes or emotional moments from the film that resonated with you. Discuss how the film made you feel and why it left a lasting impression. This will help your audience connect with your viewpoint on a deeper level.

Remember, a strong review not only shares your opinion but also provides evidence, analysis, and engages with different aspects of the film's execution.