Marionette and immature are very similar when it comes to lyrics.
(don't) leave me alone and GAME are musically very similar to each other.
Lyrically 1 LOVE and GAME are quite similar.
Together When... and CAROLS somehow reminds me of each other every time I listen to them. I don't know why. o.O
And you mentioned how SEASONS and Life do sound a lot like each other. I have never realized this.
I guess these are the songs that came to my mind. ^^