If a score is low enough, a game is probably junk. However, some games deliberately feature old designs that are still of interest to certain gamers (Etrian Odyssey and the recently released Dark Spire). Sometimes get major deductions for being short (which might not bother some consumers). Point is, you ultimately need to look out for your own tastes. If there is a game that interests you, carefully read the reviews to see why the scores are what they are. If a game is getting an average of 80% because it's kinda short and has no multiplayer (but is otherwise good), you might like it just fine if you don't care about length and don't use multiplayer modes.