It's always strange to me when people argue that a game can be worse for having additional, but less than exceptional, modes. How many stars should Dead Space 2 be knocked down for having mediocre multiplayer? Should the exclusion of a multiplayer mode have hurt Dead Space 1's score? Should Left 4 Dead have had points deducted because its singleplayer is just multiplayer with bots?
What I care about is how much fun a game is and how highly the experience is recommended. Not the whole package, not every mode averaged together, but whether or not it's worth picking up. If someone visiting the site can't be bothered to read a review and note why a game is getting the score it is, then the fault is theirs if they think they should buy Singularity for its multiplayer component.