This is a game for ATARI ST mono emulators. It is written in GFA BASIC 3.6. It is not tested on a real machine and it is possible, that it can't be run on it. You can try to run XSQUAREA.PRG or XSQUAREA.GFA in a GFA BASIC interpreter. XSQUAREA.PRG runs with the emulator hatari 1.8.0 and its built-in EmuTOS-image (https://hatari.tuxfamily.org/download.html). XSQUAREA.PRG also runs with Steem v3.2 and the TOS-ROM tos1.02de (http://steem.atari.st). It isn't compatible to STEmulator. GFA BASIC was chosen as programming language to write a program compatible to EmuTOS.

XSQUAREA.PRG can be played with one player (cursor keys) or two players (keys: w a s d). You must collect all the flags and avoid crashing into holes or bottles. You can't navigate on the space fields and you are invisible on the fields with the question mark. The moving direction can only be left upwards, right upwards, left downwards or right downwards.
Xsquare is also one of the BrowserBasic 2.05 games and a DOS version (2000) also exists.

This game shows a good performance with hatari 1.8.0, if a 8MHZ ATARI ST mono is chosen. But Omikron Basic seems to run faster than GFA Basic. The HORISCRO ASM game (2016) written in assembler runs faster and also seemed to run much faster on a real machine.