what is collateral? would 6 steam game keys be classed as collateral?
collateral is something that the lender can sell for 120% (ish) of your loan amount. on your case it's 0.144
BTC.
and you can't use steam keys as a collateral... you know those keys, you can easily use them.
btw, read
this sticky about collateral and you'll see what is a valid collateral and what is not.