This one's really all over the place. The starting premise of 'I want to marry for love', then not actually bothering to find out if you'd like the other person... Not a great start. And deciding that the best way to end it would be to force the other person to break up with you... Ugh. Then the prince somehow both spending all his time with the other person for 'evidence', but somehow also knowing everything about the villainess while the villainess never found out anything about her target...
I think it's also the first example of a common trope I dislike in these - it's a story where a 'princess' does little and gets swept off her feet by someone else solving the problem in the name of love. Sound familiar? Since that's probably one of the most common clichés around, so if you want to do that story, you have to do it very well - and this didn't. The fact that the label 'villainess' is slapped over the 'princess' part didn't change how any of the characters acted. That, combined with an incredibly incompetent antagonist, means the stakes are never very high and I'm never invested.
This one isn't offensively bad, but it's incredibly lacking.
For my reference, the best to worst so far:
1-2, 1-3, 1-1