About this problem I found this conversation on steam:
x asked this:
I can't play with subtitles. They don't appear. Someone has a solution ?
y gave this answer:
I have the same problem.
On the store says interface, voices and subtitles in English, also three screenshots show subtitles enabled but I can't figure how to enable them.
I've the original floppy version and it allows to change some settings like keyboard, sound card, video card and language (for subtitles only, it has no voice) before starting the game.
On the other hand I have also Shadow of the Comet (the game engine is very similar) on both floppy and CD-ROM and the CD version allows to choose between voice only, subtitles only and voice with subtitles, all settings including subtitles language (voice is available in English only) can be changed while playing.
Both games use the same names for the subtitle files:
D.CC4 for German
E.CC4 for English
I.CC4 for Italian
S.CC4 for Spanish
T.CC4 for French
I looked in the game folder and it contains E.CC4 and S.CC4 so in theory it must have subtitles in English and Spanish...