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First of all, you don't need to download each version to play the game, the latest version always include previous contents. If you download 0.3, it will also include all 0.1 and 0.2 contents. 

For app not installed error, make sure you have enough storage space for installation. Ideally and from my personal experience, make sure  you have at least 4x the app's size. So for Eternum, it's suggested to have at least 5. 5GB for safe installation. 

If you are wondering why you need such big storage space, here is an explanation where these are used:

• The first portion is used when you download an app. If you have successfully finished installing, you can delete this download for space. 
• The second portion is used when you open the package installer, which parses the application data, etc. After the installation is finished, package installer will clean itself giving you space it used earlier. 
• The third portion is used when you actually click Install button, which well you know, the system actually install the app. If you have installed previous versions and overwrite it, you will retain the space you have before. Otherwise this space will be used for the app. 
• The majority of fourth portion is actually not used for the game itself but for the system itself. The system itself needs a few extra spaces available to install apps properly otherwise it can cause apps to not get installed (which is common for Ren'py games).