Simply amazing. The scope and polish of this game really surprised me.
I respect the difficulty. This isn't just a feel-good, now-where-am-I-supposed-to-go game. This is actually challenging and overcoming each challenge feels rewarding. After the first time I managed it (and it took quite a few tries), I now find that I can beat the core and outrun 66 every time. Makes me feel like I actually got better at this.
All in all, the creator of Cave Story would be proud. Congratulations.
Please hurry on the sequel.