Board Thread:General Discussion v2.0/@comment-27234286-20151118175310/@comment-27739081-20160205140421

In all honesty, if there was a sequel, I think you would have to put in your save files (or it would ask you craptons of questions about what you did/did not do in the first game). Then it would use that to kind of continue along the plot that you set in Undertale 1.