The game isn't really that difficult if you just play on the normal difficulty setting while you have the option of multiple difficulty settings, there isn't much of a replay value. (gearnuke.com)
There are multiple difficulty settings in the game, with a beginner difficulty which allows you to flow easily through the game. (darkainarts.com)
The additional modes are individual boss battles where you fight a few rounds specifically against the 2 bosses in the game on multiple difficulty settings. (thevrgrid.com)