Line-it is one of a series of drawer boxed card games from Gigamic. It's a card drafting game designed by Tim Juretzki where the 2-4 players are trying to build an ascending or descending number line.
The game is played with a deck of cards numbered 1-100, plus 'bet' cards that show a 3, 4 or 5. The number cards come in red, blue, yellow and green. Each round, there's a market display of cards equal to the number of players plus two. Players must draft a card and either play it immediately to their line or take it into their hand, tho' players ca never have more than two cards in hand. If you cannot play the card you draft and you don't have the capacity to take it into your hand, you must 'complete' (collapse) your line and start another: you remove and discard three cards from the line and transfer any remaining cards to your score pile, where they'll be worth one point each. Obviously then, you want to build lines as long as possible, and certainly more than three cards long in order to score...
Except... Except that each round there will always be two cards left over from the draft. These are placed above above their corresponding colour/symbol icons where they are considered to be 'jackpot' cards. If you have three cards of a particular colour in your line you can immediately claim all 'jackpot' cards of that colour. That can mean it can sometimes be a viable strategy to go for a colour match even if that means accepting a larger jump in number from the last one in your line.
There are also the 'bet' cards. Take one of those in the draft and you are betting that you will place at least that many more cards in your line before completing it. If your bet is successful, you take a token giving you that number of points but if you fail to satisfy the bet (ie: if you are forced to collapse your line before you've added the requisite number of cards) then you take that number of penalty points...
Line-it then is a light, colourful, easy-to-play card game. It especially favours card counters who play the odds but it makes for a family friendly filler-length game. It's distributed in the UK by Hachette Boardgames.