Now, for what I have researched, there is a vague version of the credits listed in MobyGames. However, seeing how there were no composers listed here, I might assume that Suguru Ishida was responsible for composing the whole soundtrack of Chopper Attack or Wild Choppers (ワイルドチョッパーズ).

To back this up, I will prepare several sources that I have found where the majority of the Internet would credit them a lot in their favor of composing the game itself.

1) https://vgmdb.net/artist/1086 (Even though the game is not listed among their works, you can refer to this as the main reference for the other links later)

2) https://vgmdb.net/album/65034#:~:text=Based%20on%20%22Mission%207%22%20from%20Chopper%20Attack%2C%20Composed%20by%20Suguru%20Ishida (According to this clue from the Playing with Power! band, they have credited this composer for the game itself such as Mission 7, so there is a possibility that this person might have composed the whole soundtrack altogether)

3) https://www.vizzed.com/videogamemusic/game.php?id=8941
(This website also credited the composer's name for each of the soundtrack, which means this person did the composition alone)

4) http://vgmpf.com/Wiki/index.php/Suguru_Ishida
(Even this website stated that this composer actually composed the soundtrack of this game)

5) https://www.discogs.com/release/9139179-Various-Tribute-Album-64#:~:text=Not%20Your%20Father%27s%20Tiger%2DHeli%20(Chopper%20Attack)
(Another reference added from the second link, where the band again credited this composer's name)

6) https://w.atwiki.jp/gmcomposer/?cmd=word&word=Suguru%20Ishida&pageid=14#:~:text=Embrace%20the%20season-,Suguru%20Ishida%20_,-SFC%20DEAD%20DANCE
(Here, you can find the composer's name and all of the games they have composed in the list given)

That's it, now to say about the credits, none of them actually appeared in the English and Japanese versions of the game itself. So, it's quite a mystery for it to happen like that. However, I hope I was able to help you in finding the composer you're looking for. Take care!