This is the card game everyone knows as UNO, in its widely played browser form (usually titled 4 Colors): match the top card by colour or number, play action cards to skip, reverse or make the next player draw, and use wilds to change the colour when you're stuck.
The goal is simply to empty your hand first — but the action cards mean a winning position can collapse in one turn, which is exactly why the game has survived family arguments for fifty years.
Match the top discard by colour or number. Skip, Reverse and Draw Two change the flow of play, and Wild cards can be played on anything and set the next colour. First to empty their hand wins the round.
It's a browser version of the same card game — commonly published as '4 Colors' — rather than Mattel's official app. The rules and cards are the ones everyone knows.
You draw from the deck. In most versions, if the drawn card is playable you may play it immediately; otherwise your turn ends.