Then, responding to those who have said he’s “only doing this for the money", Szymanski tweeted: “Yes, no fucking shit. I make games for a living. If I didn't want to earn money from them I wouldn't charge money for them.”
The game follows the premise of being trapped in an underwater submarine out of necessity to capture deep pictures.
In the only perfectly logical interpretation of the comment, you would be correct. Unfortunately, humans are not always perfectly logical and will often say things that are illogical. The most common meaning intended by the phrase "this is a $5 game" is the illogical one of presenting it as an objective fact.
I refuse to believe that this is the first time you've encountered an illogical statement.