If a game is overly 'padded' with unfun content then it won't actually be fun and I'll stop playing it. I've always done this. Sometimes I only enjoy the first few hours of a game, then hit a section of grindy or boring content so I stop playing.
Then the trick is to make it not so fun as to get bored with it, but so barely not unfun as so you keep playing.
As well remember the conditions
1) The game must be fun
2) The measure of how fun the game was is time
Thus if the game has a lot of padding but is still overall fun... then it will, to your metric, be more fun then a game that was a blast but only lasted 10 hours.
Which is why it is important when measuring Terraria... Was it 10 hours of fun spread over 200? or was it 200 hours of fun?
I like games that last a while (It is why I don't like the current batch of point and clicks... they are extremely short... too short to be enjoyable for me) but I have long since recognized the difference between a 20 hour blast and a 50 hour fun time.
If a game is overly 'padded' with unfun content then it won't actually be fun and I'll stop playing it. I've always done this. Sometimes I only enjoy the first few hours of a game, then hit a section of grindy or boring content so I stop playing.
This happens to probably 95% of the MMOs I've played.
I can never get past the midgame slog. It is what kills me because MMOs are based off of two things:
1) The start of the game being fun because of its brisk system and fun early game bosses
2) The end game where the game starts to be unlocked.
The Mid game slog is just outright terrible. Heck for Tera I never got past the starting area as it is the WORST game EVER when it comes to the grinding slog.