Mario Oasis is an enjoyable, medium-difficulty rom hack. The challenge of the game varies amongst worlds, with some levels being harder than others. There are some levels with alternate exits, and some of those levels will also place you on a different place on the map upon completing the level…
There is overworld exploration in this game, and it is not strictly about level play. Look around! Use those hammers wisely!
Three worlds are present, plus a STAR world which is accessible by warp whistle. 40 levels in all, many with bonus sections connected by pipe or invisible note block.