Earlier quoted context omitted.
Actually if that's what you want I'd advise you to buy a windows 10 tablet. They run old (and gog.com) games and come with decent mouse emulation and actually last 4-5 hours on battery. Taking games like Spelunky on a 400 gram tablet with you for on the train/plane is nice. Even something like Civ 4 is playable.
Just curious: how the heck do you play Spelunky on a touchscreen? That game is hard enough on keyboard or gamepad, I can't imagine playing it on a touch screen with any degree of success.
TxK, Persona 4, Binding of Isaac, etc were the icing on a great cake.