Our Unity based web games use about 700 MB of memory on its Chrome tab. In addition, they use about 200 MB of memory in the GPU process. Customers can see how much memory their Chromebook is using by following these instructions: https://www.samsung.com/us/support/answer/ANS00040957/
We advise 2 GB of RAM as the minimum for all Unity games but 4 GB of RAM is highly recommended. If you have 2 GB you must make sure that the game you are playing is the only application/tab running including extensions.