Jackal is an action shooter game for the Nintendo Entertainment System.

RayofJay has given the whole game an overhaul. Palette changes, complete level layout changes, enemy logic changes (AI/timers), enemy health, bullet speeds, countless timer values, Power up function, death decrements your weapon level instead of resetting it, gaining weapon upgrades allows you to do more damage now, screen repeat function to make the game longer, double digit life count, randomized enemy locations (a select few) to name a few.

Some have claimed this game is unplayably hard. Yes, it is very hard, but, once you know the secrets and tricks, it's really not bad at all. I recorded myself completing this hack with no continues.
https://www.youtube.com/watch?v=MnU5LlA1t-A&t=116s

Expect to die a lot, though. My modification that only decrements your main weapon power instead of resetting it to zero on each death is critical for this hack to be playable.

Version 2.15: The hack was broken up into several patches to allow for customization and difficulty selection. Additionally, there is a patch to modify the jeeps' bullet direction.

Database match: Jackal (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20180803-121122)
File SHA-1: 86C392A1D9A731FA48E148AFBE60AF75F918CB5A
File CRC32: 2E52D091
ROM SHA-1: 813E6A8BC0A502BB393F8729B1BC19836D5421A5
ROM CRC32: 1D5B03A5