In most classic Mega Man games, the boss rush just dropa few health/weapon refill pickups between bosses (as it's the case here), however, I'm planning to add custom difficulty settings to accommodate for different players that want the game to be easier or harder, such as:
-Enabling/Disabling enemies respawning after leaving a room
-Toggles for mid-level checkpoints and pre-boss checkpoint (I'll take boss rush checkpoints in consideration when working on this feature)
-Multipliers for damage dealt and damage received