First, it depends on what your definition of "Sabeans" is. There were many Muslims, historically, who believed the term applied to the followers of the Greek mystic/philosopher Hermes Trismegastus, so if those people were correct, then some Hellenic believers were also saved.
But more importantly: so what??
The OP was "Is Islam the only big religion that condemns everyone else to hell?" not "Is Islam the only big religion that condemns all non-Abrahamic faiths to hell?"
I answered the OP, not what you imagined the OP to be.
Except that most of us that have been here awhile - know Islam includes the other Abrahamic religions, and certain so-called "true" seekers whom haven't found Allah "yet," and says they may not be going to hell.
Thus it IS all the rest that they think are going to Hell. Thus Polytheists, Animists, Atheists, and other unaccepted groups, are supposedly going to Hell.
Quran Surah 22 -
22.3 And yet among men there are such as
dispute about Allah, without knowledge,
and follow every evil one obstinate in rebellion!
22.8 Yet there is among men
such a one as disputes about Allah, without Knowledge, without Guidance, and without a Book of Enlightenment,-
22.9 (Disdainfully) bending his side, in order to lead (men) astray from the Path of Allah: for him there is disgrace in this life,
and on the Day of Judgment We shall make him taste the Penalty of burning (Fire).
22.11 There are among men some who serve Allah, as it were,
on the verge: if good befalls them, they are, therewith, well content; but if a trial comes to them, they turn on their faces: they lose both this world and the Hereafter: that is loss for all to see!
22.12
They call on such deities,
besides Allah, as can neither hurt nor profit them: that is straying far indeed (from the Way)!
22.13 (Perhaps) they call on one whose hurt is nearer than his profit:
evil, indeed, is the patron, and evil the companion (or help)!
22.14 Verily Allah will admit those who believe and work righteous deeds, to Gardens, beneath which rivers flow: for Allah carries out all that He plans.
22.15 If any think that Allah will not help him (His Messenger) in this world and the Hereafter,
let him stretch out a rope to the ceiling and cut (himself) off: then let him see whether his plan will remove that which enrages (him)!
22.16 Thus have We sent down Clear Signs; and verily Allah doth guide whom He will!
22.17 Those who believe (in the Qur'an), those who follow the Jewish (scriptures), and the Sabians, Christians, Magians, and Polytheists,-
Allah will judge between them on the Day of Judgment: for Allah is witness of all things.
Interesting - where is the actual cut off? Magians or Polytheists? Another text tells us -
2.62 Those
who believe (in the Qur'an), and those
who follow the Jewish (scriptures), and
the Christians and
the Sabians,- any who believe in Allah and the Last Day, and work righteousness, shall have their reward with their Lord; on them shall be no fear, nor shall they grieve.
(I get a kick out of - "those who follow the Jewish scripture, -
AND the Christians," - most of whom are obviously trinity believers.)
Sabians - When relating to a religion it means one who left his former religion and was even a title of
Muhammad for not being part of his tribe's faith.
[4] From such a root and in the context of the Qurʼanic passages, it may refer to all people who leave their faiths, finding fault in them, but have yet to come to Islam, -
Sabians - Wikipedia
According to Xenophon, the Magians sing hymns to
the rising sun and
all known gods.
22.18
Seest thou not that to Allah bow down in worship all things that are in the heavens and on earth,- the sun, the moon, the stars; the hills, the trees, the animals; and a great number among mankind? But a great number are (also) such as are fit for Punishment: and such as Allah shall disgrace,- None can raise to honour: for Allah carries out all that He wills.
22.19
These two antagonists dispute with each other about their Lord: But those who deny,- for them will be cut out a garment of Fire: over their heads will be poured out boiling water.
22.20 With it will be scalded what is within their bodies, as well as (their) skins.
22.21 In addition there will be maces of iron (to punish) them.
22.22 Every time they wish to get away therefrom, from anguish, they will be forced back therein, and (it will be said), "Taste ye the Penalty of Burning!"
22.31 Being true in faith to Allah,
and never assigning partners to Him: if anyone assigns partners to Allah, is as if he had fallen from heaven and been snatched up by birds, or the wind had swooped (like a bird on its prey) and thrown him into a far-distant place.
*