About the Browser version (HTML5) :

The game is fully playable in HTML5, but it might get some very dips in framerates when there are plenty of enemies nearby. The inputs might also get stuck on pressed, requiring you to press them again to unstuck them. That's the main reason why I suggest players to instead download the Windows, Android or Linux versions of the game, which are much more optimized. But the game is fully playable from start to finish.

About the Android version :

The game is fully playable and optimized to play on your Android device. It being a phone, tablet or computer. Just note that there is no touch screen compatibility aside from menu navigation. That's why you should play with a mouse & keyboard or a controller. Most controllers should work, some can connect to your phone via bluetooth, that's what I personally do. 

About the Linux version :

The game is fully playable and optimized to play on your Linux device. But I noticed a few framerates dips in the last level. This might just be my Linux computer being a bit too old though. Let me know in the comments if you also have framerate issues.