So, it's a 49kb ROM located on first 3 pages and starting from the second page - pretty standard approach - no mapper needed. I tried to play the game a bit and found it pretty much unplayable with the current keyboard layout. IMO the current buttons assignment is horrible and unless some customization is possible, the game will be a pain to play.
Thank for the feedback , i'm used to play it with 2 buttons controllers on MSX, we'll try to find better layout 
The option to choose cursors in a MSX is esential 
If it would not be possible to change to cursor keys, it would be frustrating to MSX people. I remember having all time discussion with my classmate who has ZX Spectrum for a long before, and we never agreed which layout is best. Now i understand that it is like always - whatever you get used to first is always the best If you don't have time to implement settings screen, there might be solution to have to layouts, and you press something (say, cursor key) at boot to change to that layout
I did some testing, and here's the feedback. It's was done as a contribution, and not as criticism, ok?
BTW: great graphics!
1) Compatibility tests
- Sony HB-F500P: passed
- Toshiba HX-23F: passed
- Sony HB-10P: passed
- NEOS MA-20: failed
- Acid1Test: passed
- Acid2Test: failed
- Turbo CPUs: passed
2) Other issues:
The controls sometimes feel a bit sticky/unresponsive. Enabling the turbo seems to alleviate that.
3) Suggestions
- It would be nice to be able to press STOP to pause the game
- Please add joyMega support. This way we could have specific buttons to FIRE and drop TNT (and START to pause)
- The name input screen should also accept direct typing
- Some background music is welcome and improves the immersion
- Since the game is well-behaved with turbo, please enable it as a courtesy on machines that have the CHGCPU BIOS call
4) Some thoughts about the directional keys controversy
This definitely is where the game needs more polishing. During the tests, I kept struggling all the time with the alien QAOP+SPACE+CTRL nightmare. The traditional directional+SPACE+M/N control scheme of the MSX would provide a much more pleasant experience.
My suggestion for the key/button mapping would be:
- UP/DOWN/LEFT/RIGHT: MSX Directionals
- SPACE, SPACE+LEFT, SPACE+RIGHT: strike
- N: jump
- SPACE+UP, B: fire
- SPACE+DOWN, DOWN+B: TNT
- STOP: pause
On an MSX joystick it would be:
- UP/DOWN/LEFT/RIGHT: directionals
- T1, T1+RIGHT, T1+LEFT: strike
- T1+UP: fire
- T1+DOWN: TNT
- T2: jump
On a Megadrive joypad, it could be:
- UP/DOWN/LEFT/RIGHT: directionals
- B, B+LEFT, B+RIGHT: strike
- C: jump
- A: fire
- DOWN+A: TNT
- START: pause
But I wouldn't worry about a key remapper just to try to workaround for one or another model that have poor direction key design. It would just add a lot of unnecessary code, while 99% of the other MSX models feature great directional keys, even better than the horrible inverted T of modern PCs or those ridiculously small up/down keys of the modern Macs.
IMHO, the best approach would be to do the same that nearly all MSX games do: to support both the directional keys and the joystick simultaneously, without need for any configuration. This allows the user to change from one to another mid-game, without any boring configuration/restart/etc.
Then, on machines that have poor directional keys (Philips VG-8010, Casio PV-7, Hitachi MB-H1 mk1) or no keys at all (Zemmix consoles), people will do what they have being doing for ages with all other games: use a good joystick.
Thank you for your feedbacks. They are welcome.
About the cursors key, I think that noboby read our answers.
We agree fact that peoples who don't have a good keyboard can use joystick.
Best, use joystick for all action games, you was lucky to have a computer with that. 
