[ronyfadel]

I’m not too sure about algorithms?

You can get away with making a working, performant (basic) engine with some neat functionality nowadays without delving too deep into algorithms or using any advanced data structures.

It is a good exercise in “real coding” though.

[brandmeyer]

Off the top of my head, there's pathfinding on a navigation mesh, mouse hit-testing and FOV pruning with a space partitioning tree, triangle mesh sorting. You can also do some agent work by building up an automated opponent.