Pulstar by Aicom/SNK, released for the Neo Geo in 1995.
SNK's Neo Geo is generally as the powerhouse monster console of the 1990s, and with good reason. Nearly every game released for the system went to great lengths to make sure you were in awe of the graphical fidelity. Upon it's release, Pulstar was one of the most incredible looking shooters ever put forth.
It is worth noting that the game was developed during a period when the aesthetic was starting to become enamored with the pre-rendered CG look, as opposed to pure pixel art. The look was popularized in games like Donkey Kong Country and Killer Instinct, and was regarded as "above 16-bit." The style was used to a degree in this game, with mixed results; sometimes it looked wonderful, and sometimes it just seemed to clash with the rest of the game's style. The novelty carried it through, but in hindsight I rather wish they'd gone with a purer pixel art style.
The game is regarded as a super-charged homage to the best of the space-shooter genre (specifically R-Type, a game which shares much in common with this title). There is some thought that the two games share a development lineage, as Irem became quite closely intertwined with SNK, though we will never know for sure. A play of the game does present some particularly familiar elements, however.
A lot of Neo Geo shooters are regarded as being quite easy (are you kidding?) and Pulstar is considered to be on the far end of that spectrum; also true to its heritage, a lot of pattern memorization and strategic play is necessary for survival. Make proper use of your weapons and powerups and maybe you'll stand a chance..
Pulstar is on a short list of must-see games for the Neo Geo which aren't fighters or beat-em'ups. Although many gamers are very tired of horizontal scrolling shooters after all these years, interested players eager for some fresh sights and sharp challenge would do well to step up and experience this game!