Very slow start, but it ramps up and by the end it's enjoyable.
The powerup system is a breath of fresh air in the Megaman clone landscape. Customizing your character, making them overpowered and then absolutely smacking the bosses in stages that gave you some trouble earlier is extremely fun. The downside is that some stages seem basically designed to be hell unless you already have some specific things unlocked and equipped, but if you do, those stages are often trivialized.