The game is a great throwback to the first FPS games: a mix of Catacomb 3D, Wolfenstien 3D, Doom1+2, and, in some regards, Quake. However, the graphics mostly resemble those of Wolfenstien, apart from a few modern touches. There's even the option to lock the Y-axis (no looking up or down) just like in the first FPS games. The action fast, the weapons satisfying, and the modern RPG elements give a sense of progression without being overly complicated. I can whole-heartedly recommend this game, but it's not flawless. The game is very easy and, because of that, very short. I'm a casual fan of retro shooters and was able to beat this game in two afternoons on the hardest difficulty while dying only on the bosses and some later levels. There is some replayability with different skills and weapon upgrades and hunting for secrets or speedrunning if you are into those things (I am not) and Hardcore difficulty which erases your progress upon death. You have a limited pool of lives and cannot save/load the game - this shouldn't be a problem (I've started with 3 lives and finished the game with 20+ lives) but the fact you cannot save whenever you desire might be a problem, although each level usually takes less than 10min. to finish (that's with exploring for secrets) and each stage consists of no more than 4 levels, but an option to save & quit would have been nice. But those are IMHO the biggest gameplay problems this game has. If you dig the graphics and old-school shooting this one is very enjoyable.
Robo Rumble, or Reflux, as it's also known as, is a strange mix of real-time strategy and a logical puzzle game. Each mission has pretty much the same goal - destroy the enemy. However, it's never as simple as just building up an army and assaulting the enemy base. Each mission is a problem you must solve using the tools given to you at the start of the mission. Usually, you need a proper army composition. Sometimes you must hold key location, or even time your attacks correctly. This, unfortunately, means that some missions have one solution, so the replayability is minimal. You do not gather resources, rather you are given a set amount of money to build your army, and if any of your robots get destroyed, that money is refunded - so you need not worry about running out of funds. You can mix and match robot parts to tackle the task at hand. You combine of chassis and weapons that suit your needs plus special modifiers like rapid-fire or extra shields (these are usually non-essential, but can make the mission easier if used correctly). All this affects the robots price and allows some for experimentation. The graphics and sounds are nothing spectacular, and in my opinion, had't aged well. But they don't really influence the gameplay. Also, the UI is minimal. All-in-all whether you should buy the game or not depends on what you seek in an RTS. If you like base building and managing the economy, this is probably not for you. However, if you prefer to focus on just on controlling your units and like to be challenged by different mission types, this game might be up your alley.