Use a short sentence, and then follow it with some reasons to back up your reaction.
You can also refer to the work that you are reacting.
It’s okay to critique a book or film, but you don’t have to be rude and nasty!
Remember that critiques without evidence and clear examples is always baseless and boring to read.
Of course, your tutor expects that your reaction will be thoughtful and sophisticated, so do not despise including a bit of analysis and background information.
Some students think that reaction papers give them an absolute freedom of expression and go to extremes with criticism.
It’s a reaction paper, so don’t be shy to express your own thoughts.
In this case, there is nothing weird about all these “I feel” and “I think”.
Remember, you need an entire draft written carefully from the beginning to the end to understand what exactly you should include into the first paragraph of your finished work.
Your overall point must be stated clearly in the first paragraph and you can’t do it without having a full picture of your paper.