Extremely underrated Elder Scrolls spinoff. The biggest issues with the game are technical. The DOSBox emulation is just bad. I suffered from frequent crashes playing with Bethesda's DOSBox config for the Steam release until I followed the community guide to upgrade the game to the Glide rendered version with superior graphics. I never crashed after doing that. Unfortunately, I suffered from terrible lag instead that even made me fall through the ground during a loading transition at one point. It was a pain to say the least. I don't know which I'd recommend between the default setup and upgrading to the Glide version. It's probably best to just see which you think feels better.
However, when you get past the technical issues that come with emulating Redguard, you find an incredibly overlooked gem. It's a very fun action adventure spinoff with some of my favorite writing in the series. I highly recommend reading the prequel comic, the manual, and the Pocket Guide to the Empire 1st Edition, which all came with the game (you'll have to find the PGE online however). They provide a bunch of amazingly written context that is all referenced in the game itself. I think that out of all the games in the series, Redguard does the best job at making you feel like the characters in the game truly inhabit the world of Tamriel with Morrowind at a close second. The dialogue is amazingly realistic and full of depth. Bethesda really makes you believe that characters like Cyrus and Tobias are seasoned adventurers who have traveled the continent or that the people of Stros M'kai are suffering from the Tiber War and the fierce rule of the Imperials. Listening to all the dialogue the game has to offer is absolutely worth it. The story itself is just fantastic too. Cyrus's inner conflicts and his quest to save Iszara and the larger drama at hand surrounding the Imperials is gripping to say the least, and the story's climax is amazing. It's thoroughly excellent from beginning to end.
The gameplay of Redguard is often heavily criticized online, but I found it a lot of fun. The sword combat is pretty different from what you'd expect from an Elder Scrolls game since it's a spinoff, but I found it pretty fun and rewarding after getting used to it. It's fun to learn enemy patterns and the best ways to strafe around them and counter. The bosses are a little underwhelming though. They're often gimmicky but not in a terribly exciting way. They're not bad, at least. The overall adventure gameplay is very fun as well. Some of the quests can be done nonlinearly, and the experience of adventuring around Stros M'kai and trying to figure out what to do feels very rewarding. The game doesn't hold your hand. You're given a lot of hints and bits of odd information, and it's your job to figure out how they all fit together and even how the quests all fit together into the narrative at large. Very little in the game is optional, and it feels immensely satisfying when you figure out how things click. It's probably my favorite part of the gameplay. This type of discovery and puzzle solving gameplay extends to the dungeons, which have more traditional puzzles. They are true head-scratchers that will force you to stop and think for a long time. It's a shame the main games don't have dungeon puzzles like these. There's no shame in resorting to the Redguard Companion, the official guidebook, at times, but it feels amazing to figure out the solution to a puzzle in Redguard yourself. The only real gripe I'd take with the gameplay is that the controls are weirdly slow. You get used to it, but every action has an odd delay for like half a second. Was only worsened by the lag of the Glide version.
Overall, I highly recommend playing Redguard, especially for how cheap it is and how often it goes on sale. It's such an amazing spinoff that doesn't get enough recognition. I can only hope that Bethesda will one day make the scrapped sequels Eye of Argonia and Paradise Sugar.

It just works.