As I said above, I felt the exact same way for a time. In fact, I put it on the shelf for several months (see my review) on p. 25. Finally, I gave in and looked up how to get the first couple e-tanks, and how to get to the first couple bosses. Once you get past this part and get a little less underpowered relative to the enemies, and can explore with a little more abandon, the game really gets better IMO, to the point where it ended up being one of my favorite hacks of all time. But, admittely, the first time I sat down and played for like two hours, getting only bombs and a couple missile tanks and loading states constantly, I was really disappointed despite how good it looked.
Eris takes some getting used to, but, the rewards in the end are worth it.
Eris takes some getting used to, but, the rewards in the end are worth it.