I decided to see what new prologues were out on Steam since last I checked, and I found a couple that were pretty fun:

• Dark Gravity: Prologue
  

  2 hours playtime

  no achievements

• BioGun: Clinical Trial
  

  2 hours playtime

  no achievements

Dark Gravity Prologue: SHMUP. Standard movement, RT shoots, RB toggles auto-fire, LT shoots your secondary weapon (has ammo but slowly refills when not in use), and the A button dodges. Most shot patterns can be avoided just fine with basic movement (at least on Normal mode), but there are still a few where you need to use the dodge button. Also, even after going through the tutorials, it’s easy to forget about your secondary weapon.

The prologue has four levels, but one of them is in a branching path, and the game won’t let you go back to the other level once you’ve made your choice; the only way to play the other one is if you start a new campaign and replay the first level again. You also get to see a preview of the main game’s campaign paths, which is how I know you have to play through half of the main game three times in order to unlock all the levels.

Once you do, though, you can play them in Single Mission mode in any order and on any difficulty, even if you only played the campaign on normal mode. That’s how I tried out hard mode: it has the same number of enemies in the same formations at the same locations, but they shoot more projectiles, requiring the dodge mechanic a lot more. Some levels also have an extra boss/phase at the end; level 1 and 2a were fine for the most part, but 2b’s additional boss had some cheap laser attacks, so I stopped playing when I lost there. Still, normal mode is worth playing through, so I can recommend it.

BioGun Clinical Trial: Twin-stick Metroidvania. Left stick moves, right stick shoots, and LB jumps. As with any Metroidvania, you’ll get upgrades as you progress, such as dashing (RB), hovering (LT, but can be changed to the jump button in the options), and a stronger, longer-range gun that uses ammo (RT). The game has that “hold a button to heal after a delay” mechanic that I hate, and you can’t even move while healing unless you buy a specific upgrade and have it take up your lone upgrade slot (which can only be swapped out at save points). Once again, a game invents a problem and sells the solution instead of doing things right from the get-go. This type of stuff is why I’ll never understand the player-side popularity of RPG mechanics: pay-to-win was always its logical conclusion!

Level design is okay, though I could easily see the full version ending up as one of those games that doesn’t really have much of a difficulty curve. Enemies have fair attack patterns and no stage hazards will catch you off guard, but there weren’t many parts I had trouble with outside bosses, which can have some cheap hits (like the fish that’ll charge at you, even if you’re on the lower level where the ceiling is too low to jump over it). There’s even an optional boss placed before you get the long-range gun, and IIRC this part is right before a shaft that you can’t jump back up, so you can’t exactly go back for it afterward. Plus, the boss itself keeps spamming swarms of the bug enemies–too many to fight off and get many hits in before the next group spawn. Still, what’s here is fine for being free, so I think it’s worth checking out.