I'll free you guys from your burden, even if I have up to 6 hours after confirmation of nothing else to do than think of a new question (nah... won't be the full 6 hours)

It's... it's... the intro-tune of Cabin Times (PSG version). You can run Cabin Times when you boot the MSX with disk 2 of The Tower of Gazzel.

it is?

it is, but we'll await wolf's reply.

right. (more time to smoothen your new question beef)

cabin times intro psg.. correct

There's echo with 60% feedback on it so it's pretty messed-up .. however since the chords are quite characteristic for the tune I decided it was doable .. bifi proved that

)^_^) Hey! Did you know there's a cheat in Twinbee?
(O_O( There is?
)^_^) Yeah man!
(O_O( Where? How?
)^_^) That's what I wanna know from you.

(^_^( "hey look, we're at MRC now as well!"
)o_O) "MRC.. IRC .. what's the difference .. just one ascii"
(^_^( "well, sonic_aka_t is gonna like us being here as well"
)O_o) "who?"

(^_^( "for the ppl who don't know us yet.."
)o_o) "..and they were happy.."
(^_^( "we're the alternative balcony folks from the alternative muppetshow"
)o_o) "..invented by that insane freak who adds echo with 60% feedback to lovely PSG tunes"

..and u reversed it

(O_O( Darn, dunno where... Where?
)^_^) Hidden behind some key.
(O_O( Wanna know how... How?
)^_^) At the very beginning.
(O_O( Really? Wow!
)^_^) Yeah man!
(O_O( Still dunno much, do I?
)^_^) Right now it's up to you again.

Is there anyone who actually took the effort to play Twinbee?

...I actually played Twimbee for about 15 minutes (!) and it took some effort.

Yeah... there are some key combinations to get an ambulance when you need it, or a harder barrier or to get a barrier and two options from begining.

I don't know about the first 2. I'm talking about the third one you mentioned.

(O_O( Still dunno what to do.
)^_^) Try pressing the Z key.
(O_O( When?
)^_^) After starting the game.

You can get the third one pressing Z + M or Z + TAB in game menu.