Simply put, this game is just far to subtle in terms of what it tries to do. Sure, the fact that this game tries to be artful and refreshing is nice, but still Dear Esther just falls short of actually engaging your interest and making you really desire to replay it to discover new pieces of information or different slants to them; and overall, really desire to become invested in the narrator's ( guy you play as) story. The game will always end the same way, but with different little changes to the enviroment each time and to the narration, however those changes never go past things like writting on the wall. And there is not really anything significant to these changes either.
*****SPOILER*****(sort of, really just an opinion)
All in all, the plot just sums up to being about a guy who is really depressed and sad about his friends having died (Sure if you play the game it goes into some detail about how they may have died, and all the finer details as to the narrator's struggle with depression on the island, and other elements and aspects to his psyche, but I won't try to spoil those). And yes, there is some further evaluation that could be done to the narrator's story, but to be honest, the game is just not involving enough to really spark one's interest to contimplate them all. After one play through, if you are decent at keeping track of the story elements and metaphors/erratic stream of conciousness that is the narrator's narration, you will have found all you really need to know about everything in the game. There is no overarching thesis or argument being said in this game. It is just a simple, hour long story. Which, to say the least, was disappointing.
Also, just to touch on the technical aspects of the game (design and graphics), there is nothing really phenomenal here either. Sure it shows off how awesome the Source engine can be, but it is of course still apparent in the game that the Source engine is in deed an outdated platform. If you are looking for a brilliant or etheral visual experience in this game, you will probably not find one depending on what your evaluation scale for graphical acievement is.