OES is a rather dark album, so a couple of light-hearted tracks provide some 'comic relief' as it were.
Ticket to Heaven is just pure sarcasm. Mark copies the musical style of the (in)famous American teleevangelists of that time. My Parties sounds like a Randy Newman song. It doesn't do much for me, but I like how you really can envision what the party looks like.
One thing I don't like about OES is how the songs are ordered. It's more or less a rocking song, then a slow song, then a rocking song, etc. I like the 'waves' to be a bit bigger.