First off - a technical correction. The Trent missal was NOT used universally in the Catholic Church, nor even the Roman Church Sui Iuris.
The Dominicans had their own missal, used within their priories. It’s essentially the mass of Rome circa 1250 AD.
Several other orders of Religious had their own missals with different rites: Norbertines, Carmelites,
The Dioceses of Toledo (Spain), Braga (Portugul), and Milan (Italy) had their own rites, which differ from the Roman of Trent.
The Dalmatian was a translation of the Trent Missal into Old Church Slavonic.
All of the western rites shared the same basics, and all were in latin save the Dalmatian:
A series of introductory prayers
An epistle reading, a psalmody, an alleluia, and a Gospel reading.
The Preparation of the Gifts (in the dominican, this is done before the mass)
The liturgy of the Eucharist with a single anaphora
The prayers of thanksgiving and the dismissal.
The Roman/Trent acquired a bunch of accretions that are properly outside the mass
The specifics varied as to what introductory prayers and in what order, and likewise the thanksgiving prayers; the anaphora text (consecration) varied very slightly.
The Ordinary form differs in that it has 10+ approved anaphora texts (Eucharistic Prayers); 4 approved for daily use. EP I is derived from the Trent text. It also changes to a 3 reading format: Old Testament, Psalmody, New Testament, Alleluia, Gospel. There are numerous rubrical relaxations - the majority of the postural rubrics for the clergy are absent. Permission to use the Apostle’s Creed instead of the Credo is present for masses for children; in Greek and Slavonic, the Nicene-Constantinopolitan creed is used. The distinctions of High, Sung, and low mass are absent; instead, the decisions on what to sing are less codified, allowing for a wider spectrum. Further, the reading cycle was changed to be 3 years long, to use more of the bible as readings, and to align the readings into themes. Also, the whole consecration is done audibly, as was proper for the pre-V II Ambrosian Rite (of Milan).
A note further on the Creed: after trent, at least 3 creeds were in use:
1 - The Roman Credo - the Nicene-Constantinopolitan Creed with the filioque added
2 - The Mozarabic Credo - the Nicene-Constantinopolitan Creed with et filios added (tiny difference, but still)
3 - The Nicene-Constantinopolitan - In Slavonic; it’s used because the Slavonic translation becomes heretical when i Synu is added.
After Vatican II, the apostle’s creed is allowed for children’s masses, and the Nicene-Constantinopolitan is used in Greek, Slavonic, and a few other languages, where the wording translated to latin procedit and english proceeds implies origination rather than transmission.
And this is entirely before referencing the 20+ other churches in full communion with Rome - almost all of whom use a 2 reading system - Epistle, Alleluia, Gospel. All of whom have multiple anaphorae (ranging from 2 or 3 for Byzantines, through 15+ for one of the Syrian rite churches).