Commander Keen get a lot of love, and rightly so, but Cosmo seems to fly under the radar. This platformer is excellent and anyone that liked Keen should absolutely play this game.
While nostalgia definitely helps one get over the dated graphics, this game is fun even for newcomers. The controls take a little getting used to, as does the aiming, but after that it's a glorious and difficult experience. While it isn't as rich as DOOM, there something to be said for the visceral pleasure of shooting down Nazis. You can spend weeks exploring and trying to beat this game in a completionist way, or you can just enjoy it as an easy-in-easy-out no commitment arcade.
It's like an evil version of Mario Kart in the best way possible. It's very dated, but VERY fun. Playing with friends is 10x better.
While I've never beaten these games, I wouldn't feel complete if I hadn't wasted countless hours trying. You can't appreciate where we're at unless you know where we've come from. Don't get me wrong, these games aren't some old relic to be tolerated. They are rich, enjoyable, and well written. That said, you will want to punch your monitor... frequently. I recommend getting a notebook and taking notes. It helps.
If you like DOOM and you like Star Wars, you'll like this game. I still haven't beaten it, but it's fun to break out and play sometimes. It is built on the DOOM engine, which some people love and others hate, but at least you know exactly the sorts of graphics and maps you will get.
The story is fun, the game play is fun, and the art is fun. If this were a triple-A title, I would be a bit more critical, but Dust is very up-front about what it is. As such, the story and gameplay all fall within expectations, and you can just enjoy the fun fighting mechanics and good level design. It's a great game, and it doesn't take too long to beat, so I think it's a worthwhile experience.
Some games have done 2D to 3D toggling, allowing you to bypass certain 2D enemies, or discover secrets not visible in the 2D plane. While this game is similar to those, it was done in a uniquely creative way. The graphics make you yearn for more. If you've played Monument Valley, it is a similar experience, but Fez did it better in my opinion. The maps are designed well and make you want to explore and experiment.
