I am no Pharo expert but will try to answer with what I know 1) Pharo download is 16 mb compressed and 58 mb uncompressed.
2) Pharo is a standalone and as such it does not need installation. Everything you need is in a single folder contained in a single zip with a single download. I dont think you can get any easier than that. So its a single task. 3) There are people who run Pharo on iOS like DrGeo. But Pharo does not support those platforms and most likely you will experience few problems with it. So its some extra work but its doable. They do represent a larger market and a very important one I agree. 4) Again I dont know the issues on those platforms but bare in mid, Pharo is a dynamic language and dynamic language are definetly not a first choice for those platforms for game because they are slower than official supported languages. Those are in iOS ObjectiveC and on Android Java. All that assuming your game has some demanding graphics. For simple graphics with not much animation and such you should be ok. Personally I think its not a good idea, because Pharo does not support those platforms well. I think that in that scenario there is a better alternative , that of Javascript + Pharo. Its possible to use JS as front end and Pharo as backend. If you dont want to code in Js there is Amber. Web apps are quite performant so you will be able to do some really impressive graphics with this recipe. You will be using also technologies that are well documented and well tested. Also there are like a ton of game libraries for JS out there. Which will lift the amount of work you will need to do for your game.
