One of the main virtues of casual games is that you don't really need to stop to think about a plot. It's usually as simple as a couple of clicks here and there, and start playing... But that doesn't mean that the game is easy to play. Just take a look at Flappy Bird.
In The Impossible Cave Free, that's just what we'll find: a game with a very simple and easy-to-understand concept but that's very hard to master, and that gets even more difficult as we advance, hooking us on to its challenging gameplay from the very first moment. However, it also might up scaring a few users.
Find out if you're in the longest and deepest cave in the world
The game is about pushing a ball through a cave in which we'll have to avoid different obstacles as well as negotiating with its own shape, as sometimes it becomes terribly narrow. The ball advances at a constant speed and we've only got to move up or down. As easy as that.
Regarding the game, we have to point out that it's extremely minimalistic, in fact, we've been playing games of this nature ever since the 80s' on Spectrum and Amstrad computers, and video consoles such as the Atari 2600. The graphics are in black and white, but they're decent enough.
It captures all the essence of casual games.
And there are a few other aspects to be pointed out: on the one hand, we can choose between two game modes depending on whether we're right or left-handed (for righties the movement is from right to left, and for lefties, from left o right). On the other hand, it's soundtrack is made up by catchy electronic music written especially for the occasion and that's the perfect complement for all the action. Very similar to Geometry Dash, a great reference in terms of casual games for Android and iPhone.
Finally, this is a free version so you won't have any trouble downloading its APK. However, there's also a full version that you can download from Google Play as a standalone or buy it through in-app purchases. The main difference is that it offers us extra lives and different checkpoints so we don't have to start off from scratch each time we die.