I and another user answered a similar question here if you're interested.

Two important things to consider here:

Firstly, until 1707 Britain wasn't unified, so we're dealing with three separate and sovereign kingdoms, each with their own crowns, each with their own parliaments, and each with their own unique religious, social and political character.

That, of course, makes it very difficult to broadly categorise (was it an invasion/conquest/coup/revolution?) the events that led to William of Orange ending up with all three crowns, as he took them all in different ways.

The second thing to remember is that 'Glorious Revolution' doesn't quite mean what you probably think it means. It's a propaganda term from the time (it was coined in a speech in the English parliament in 1689) that has stuck. 'Revolution' only acquired its modern meaning after the French Revolution of 1789.

So in this context, 'revolution' is used much more literally. It's referring to a revolution in a rotational sense, the idea being William's intervention has brought English history 'full circle' and restored the ancient rights of Englishmen as enshrined in Magna Carta, that James had so heinously violated (according to his Parliament).

Hopefully that'll explain why you had misgivings as categorising 1688 as a revolution - it's not even meant to be regarded as one.

Anyway, let's address your question a bit more directly.

it seems to me that James could have put up much more of a fight, and if a pitched battle or two had been fought it would be seen as much more of a conquest.

James did put up a fight and it took a lengthy and destructive war for William to oust him. It's just that James never had a chance of resisting William in England, which, remember, is just one of his three kingdoms. James' English, and therefore Protestant, army had no desire to fight its co-religionists for a Catholic king, with commanders, officers and men deserting in their thousands.

Rumours spread in James' camp that the king was shipping a Catholic army from Ireland that he would allow to terrorise the country - exacting revenge for the massacre of Catholics by Protestants in Ireland - in return for fighting for his English crown, further eroding the morale of his men.

James seems to have realised his army would disintegrate totally if he moved against William - better to stay and preserve what he could and hope William came to him, or better still flee to one of his other kingdoms where he enjoyed far more support. Scotland and Ireland differed vastly from England in terms of social and religious composition and James could hope for much more support in his power-bases of Ireland (Catholic majority) and Scotland (several Catholic clan chiefs/hostility to the Church of England/loyalty to James' Scottish dynasty).

To give you an idea of the state of the royal army following William's landing, when Jacobite rebellions eventually broke out in Scotland William's reaction was delayed as he wasted months struggling with Parliament for the funds to restore the evaporated army.

Hopefully this has clarified a few things. A single label can't be applied to the Glorious Revolution because we're dealing with three sovereign kingdoms and therefore three different narratives and timelines. James and his supporters fought bitterly for his crowns - the capitulation of his English army is only one facet of a struggle that lasted years.

If you've got any more questions, shoot. I could talk about this all day.