54Mbits = 6.75MBytes.
at that rate, it would take about 6 seconds to download your game.
however, that wireless adapter is connected to your internet line, which may only be 4Mbits. This is 0.5MBytes. This means it would actually take 66 seconds to download your game.
getting more towards your actual speed now...
all these numbers are maximum throughput numbers. when transfering data (like your game), you're transfering more than just that. you also have all the extra details that go with the protocol you're using (HTTP, probably). also, there will be some losses on the line.
a half-decent approximation is to multiple your speed by 0.7 (allowing for these losses etc.), thus giving you a download speed of 0.35Mbytes. This is just over a minute and a half of downloading.
add to all that the fact that the server you're downloading the game from is probably serving other people, so can't send you the data as fast as you can receive it. hence, it'll be even slower than that.
that's why it took you 2mins.