The first symphony is a work still rooted in the heritage of German romanticism, very respectful of classical forms: slow introduction to the first movement, Larghetto second.
The second symphony is frankly a tribute to Brahms, both in the orchestral colors, the themes developed (end of the first movement, the beginning of the final). Yet the symphony is surprisingly slow motion moved third after a wonderful tarantella, or continuity between this and the final slow movement (as in the 5th or 4th Beethoven Schumann).
The third symphony is, against all odds, a work of "program" inspired the character of Miriam in the oratorio Israel in Egypt Handel, and successively develops four themes: the first movement depicts slavery, the second (slow) translated the song of Miriam, the third represents the leak, and the final celebrates freedom. Yet Brahms's influence is even more evident in the first movement and especially the final.
The fourth symphony returns to the classical form purest, in a rather concise form; Gernsheim also seems to partly free from the influence of Brahms. It is a dynamic work full of ranging, with a final triumphant in the romantic tradition.
Beyond the obvious influence of Brahms, especially in the 2nd and 3rd symphonies, we may note the charm of slow movements and especially consistency, dynamism scherzos, which are often the most interesting movements of symphonies. So you get a serious music, which is probably not very original, but it is well written, and performed with application.