Short game is okay, but bad story not.
Sadly more often short is combined with bad story...
Basic progression of standard NTR plots.
1. Peaceful initial state of characters.
2. Introduce antagonist.
3. Corruption arc.
4. NTR reveal and fallen heroine.
I wish this would be true more often.
Fact is, when you make a longer game (which means more story and not more CG's), your built-up is maybe(!) better, more understandabe, and so on more enjoyable (means: you can empathisize better withe the MC) - if you like this way of ntr.
I, for example, really like to see the MC and his girl getting from "unknown" to "in love".
But I also love the idea of the rocky road (rivals to fight for your girl) and a lot of things to work out, before you will see an happy end (MC will win). But I want to have the danger, of others also getting the girl, and perfectly will show me how superior they are (sometimes with a little humilation) which will be the ntr-part of the game.
Others like the idea of the MC running a trail (so no real options) and definitly will loose the girl.
And others want to play till you get the girl, to then see some villain coming through the door, and taking the girl with them, while the MC sits there and cries...
NTR is more than simple "cheating seen from 'loser'-perspective", especially when you try to pack it into a game (which means interactivity).