It is is written in Locomotive BASIC 1.0, which is the Amstrad CPC's native BASIC (1984 by Locomotive Software Ltd.)
Viewing post in The Wrath of the MCPC jam comments
Hello...
Wow! Many years ago....thanks for explaining. May I ask one more question? "VIC 20 BASIC V2" is in the description of the following game. Is "VIC 20 BASIC V2" also a BASIC language of the same computer? Thanks.
https://itch.io/jam/jam-for-all-basic-dialects/rate/975324
Each of the 80s home computers (Commodore 64, VIC 20, Amstrad CPC, Atari, TI 99/4a) came with their own dialect of BASIC. Many were incompatible. Bill Gates and Paul Allen had their fingers in many of them and sold interpreters to these companies. Some wouldn't accept Bill Gates famous "royalties" and would rather write their own BASIC. Later on, the MSX Home Computer Standard was established and they all had the same Microsoft MSX Basic (hundred of different MSX machines, all compatible). The game you are referring to is for the VIC 20 (Commodore BASIC). So its different, and without porting / adjusting it, it won't run on machines that are not CBM BASIC (Commodore, VIC 20, ...)