I spent a few nights last week working on a little side project: one of those "idler" games that are popular on Kongregate.
The idea is to mix trading card game (TCG) elements into the idler game formula. Play cards that generate gold/second, spend that gold on new packs of cards, and strategize by finding the optimal way to place your cards on the grid.
The idea started out as a little side project for fun. But it's surprisingly been getting a lot of plays: about 5,000 per day, even though it's just a preview build with maybe an hour of content! So I'm going to keep expanding on the game, and aim for a full "1.0" release within the next few weeks.
You can try out the preview build here: https://www.kongregate.com/games/Fordesoft/creature-card-idle-wip
(Note: that link will stop working at some point in time, when the "1.0" release is out. That link leads to a temporary preview build.)