Wow I'm speachless... so this game not only actually works on MSX, but also does not require MSX2 VDP, and it is a 32k rom!
My thoughts as well.
What obscure trick does it use to have such a fast frame rate?
I was amazed at scrolling speed of Zanac but this is even faster.
Actually scrolling faster is more easy. 
When you start scrolling 8-pixels at a time, the 8x8 tiles start to work well. You can scroll the whole screen in a frame by transferring only 768 bytes.
Only for MSX2...
Yes, it's bugged on MSX1.
I do wonder if the extra wait's have been added to fix the MSX1 VDP access, if it will affect the gamplay/speed.
Oh, 
I tried to load the game on OpenMSX using SVI-328 setup and was like "Damn, it is so close to working, but yet my loader seems to fail." ...and only now I tried MSX1 setup to realize, it looks exactly same. 
VERY impressive!
I just love that you can 'go back' and the scroll reverts with you. First go and went all the way to level 8, died on my last life as soon as the boss appeared ^_^
Didn't have that much fun with a shooter in a long, long time
