Question2: can I play games by the use of altcoin or just bitcoins?
Answer to the first question would easily be poker. Though admittedly its hard to earn there depending on the caliber of opponents you face. For question 2, there are several sites that use bitcoin for gambling. Even exchange sites would allow you to play basic rolls of dice.
Well poker mostly applies to the first question as you can't really expect to go far if you play poker online with all the good players there, unless you're really that good. When it comes to the fun of it, poker also ranks at the top for me though i'm resigned to the fact that i won't really get money from it.