If you don’t have graphics cards in your computers, You might as well go to something like pythons pygame or html 5 canvas games. Even godot might be a good test for you guys as a free alternative. Seriously though, if you don’t have video cards in your systems, the best you can really do is no textured or menu based games meant for interactivity.
As for the learning curve, with ue4 it is very confusing for me as I’m coming from programming. I love the idea of the visual script, but it is combersome to learn cause you have to 1, learn the api and vector situations. You also have to learn how to establish input and weather or not you want your input to be from blueprints, or from settings from with in the editor its self. You also have to learn tricky things like setting your default map, where unity kinda just has it free flow.
I personally like ue4, but it is overwhelming and intimidating at times. Also the interface can get cumbersome for visual script untill you learn how to make functions such as pins and other things.
With unity, its straight forward with its programming in c# which is why i like it. While the dot syntax confuses me at times, its nice not to have to go through the headache of looking through blueprints, when you have the code sitting right there.
Both have there strengths and weaknesses. If you really don’t have video cards in some of your computers you are seriously limiting the learning of your students. I wouldn’t say they even need a powerful one. I have a Nvidia geforce fx 710 and it runs the editor just fine. Please consider upgrading those computers.
Anyway, its personal choice really. I think unreal is more friendly lately with start ups and students. Unity is great as well, but they allow you to make up to 100k totall from your games before they seriously start charging you for a licence. Ue4 i havent’ checked on in a while, but i believe they are royalty based.