Hardcore Gaming 101 - Dolphin Blue
Dolphin Blue is a bit of an oddity. Developed and published by Sammy for their Atomiswave hardware, it's a run-n-gun arcade game released in 2003, at a time when run-n-guns were mostly out of the mainstream. It's also very obviously inspired by Metal Slug , which was, not coincidentally, the only other run-and-gun series that was still on the marketplace at this point.
It's Metal Slug meets anime Waterworld in this 2.5D run-and-gun released for the Atomiswave arcade board in 2003.