The games is dependent upon what sort of processor the Chromebook has. As in, is it Intel-based or Rockchip-based? There are also ARM-based Chromebooks that are best suited for the Google Play compatibility, like the Samsung Chromebook Pro.

As for the IMAP, Gmail can actually do that in the settings menu under Accounts and Import. There should be a header that says Check mail from other accounts. Then click Add a mail account.