Wednesday 6 July 2011

Jet Pac Advanced

In mid-2009, Bad Beard and I worked on a hack to introduce new levels to the Ultimate Play The Game classic ZX Spectrum shooter Jet Pac as well as making a minor adjustment to game play (influenced by the XBox 360 Jet Pac game).

Here is a picture showing all the levels. Level 4 only has 2 platforms, 8 only has 1 and 12 has no platforms.


As Jet Pac is a denied game I can't distribute a snap shot of the resulting (now 48k) game, but Bad Beard managed to implement the hack as a very long set of pokes and it is fine to distribute these so I am now releasing it here as a POK file.

I have tested the POK file in Spectaculator and EmuZWin and it worked fine. I think that ZX Spin does not support .POK files and I know that ZXDS cannot handle this as the POK file is too long. I haven't tried any other emulators.

When I first released this hack on World Of Spectrum FrankT very kindly converted the hack into a form usable by ZX Spin. His instructions were 'Spin users can just copy and paste this into an assembler window and click assemble at the Jet Pac menu screen.'. Here is a link to a text file containing the code FrankT created.

Level 1 is the same as the standard game, the new levels are from 2 onwards. So, give it a try and let me know what you think - I won't be in the least bit offended if you think this is heresy and that the perfection of the original should not be messed around with.

The gameplay feature change is that if you are holding some fuel and an enemy crashes into you, you drop the fuel instead of losing a life. This doesn't always happen though, it never happens when you are standing on a platform or on the floor, your jet pac has to be blasting. It is quite subtle and so is not a game breaker .

As regards to further development, Bad Beard did suggest we create our own ships and monsters but the project sort of ran out of steam once my daughter was born and I now think any ships or enemies we created would probably be inferior to the UPTG ones so it is no bad thing we didn't.

Links:
POK file
ZX Spin assembler code