给出一组电影评论，使用自然语言处理工具（如NLTK或spaCy）分析每个评论中出现的主题，并提取出每个主题的频率。
"I really enjoyed the storyline in this movie. The acting was superb, and the special effects were amazing!"
"Unfortunately, the plot was weak and the characters felt undeveloped. Overall, I wouldn't recommend this movie."
主题分析，并提取频率：

第一条评论的主题：故事情节、表演和特效
主题频率：
- Storyline: 1
- Acting: 1
- Special Effects: 1

第二条评论的主题：情节、角色
主题频率：
- Plot: 1
- Characters: 1