I shouldn't need to talk you into picking up a game as perfect as Downwell when it's free. Heck, you should probably already own it somewhere -- PC, Switch, PS4, mobile -- because it's only $3. But, $3 is $3, and free is free.
For the next week, Devolver Digital is giving away Downwell for free on Android devices. Something was bugged with the original version, Devolver had to make a whole new app to fix it, and for all the hassle, Devolver's just making it free until September 27. Here's the Google Play page; it goes free today at 5pm Pacific. (Also, if you bought the original version on Android, read this page to figure out how to get a refund.)
We gave Downwell a 10 back in 2015 because it perfectly executes on its simple concept: A roguelike with second-to-second decision-making all while gravity pulls you down. It's one of those games that takes a while to get the hang of, but once it all clicks, you feel so fabulously competent during the long descent. If you're an Android user and you've never played, do yourself a favor and give it a download.