Criteria
1. You used capital letters at the beginning of the paragraphs, after periods, and when using proper nouns.
2. The paragraph had an introduction describing a situation as the directions asked.
3. The ideas in the paragraph were clear, and had a congruent sequence:
4. The third conditional sentences were properly written with the correct structure.
5. The paragraph had an introductory, main and conclusive sentence.
6. Punctuation marks correctly used when the sentences started with the if clause.
7. The text length was correct.

There are some aspects you should be careful. If it is necessary, study again the use of third conditional, pay attention to the grammar tense after the condition as well as in the result. Do not forget to answer everything that is asked and mention all the points that are required. It seems to be that you are getting better at using the third conditional; unfortunately your writing is not perfect yet. There are some points that you are forgetting about and checking the grammar structures, punctuation or the correct tenses in each clause can help you make fewer mistakes the next time. Your writing is really good! There is always something that can be improved, but you have learnt to use the third conditional to express regrets about a past situation. Excellent!