WARNING!!!
I just tried to purchase Just Cause 2 using the credit card option via Moneybookers and it got declined. I tried again, and again with no luck. Then I got a call from my HSBC Mastercard stating there may have been an attempted fraud. Apparently this merchant had their security compromised recently and Mastercard MADE me cancel my current card and is overnighting me a brand new card with a new number. I'm glad they were proactive but pissed that I've had this credit card for 12 years and use it exclusively (killer rewards) and have tons of accounts paid by it monthly. So, if you don't feel like having your credit card cancelled I wouldn't opt for the credit card option but rather Paypal or something else.
Looking at the payment page again I'm pissed. It says Credit Cards via Paypal bolded. If you read a bit further it says you can pay with a bank account. I didn't even get that far as I only have my checking account tied to Paypal and it takes a few days for a credit card to work with your account. My credit card was tied to Paypal but it expired a few months ago and I never entered the new information. Note to self, read further because maybe they will take Paypal with checking.
Time to try this again... Thanks for the heads up, OP.