I had to watch some Bruce Lee (1984) gameplay to understand what you were talking about with lamps and pixel rivers, and now I understand better what you meant.

Map size isn't a real issue in MOBAs. The map in Dota 2 is sprawling, and this allow the initial lanes to be pretty rigid at the start of the game and makes movement item/spells important. However there's very little "exploring", the map is known in advance, and the only unknown is about the type of the power rune and which of the two rune spots it spawn on every two minutes.

So in your context it would look more like a Metroid speedrun than an actual exploration. Players would simply try to reach the known objectives on the map as fast as possible and skirmish around the critical ones.