Putting this here because Itch reviews are currently inaccessible to the public. Below is my 1⋆ review:

This was by far the most disappointing turn-based experience that I was unpleasantly surprised by. Way too much effort was put into looks and merch, and not enough into the actual gameplay experience. There was:

• no tutorial of any kind, which may be fine but the fact that there is also no manual is flabbergasting.
• no overwatch/guarding system like in the first Steam Marines, so if an enemy was spotted around a corner with not quite enough action points to reach and deal damage to it on any significant level, there is nothing you could do but flee or sit still, and maybe guard if you have four APs left.
• no way I could see to turn your soldiers without taking a step forward, so you literally can't turn them around to face the other way if you have two APs left.
• nothing that told you that reloading is done automatically between turns.
• nothing that told you that you have to re-right-click on an enemy to confirm an attack, once it goes into the weird zoomed-in mode.
• no list of keyboard shortcuts anywhere, whether in the game, a manual, or on the website.

The list of woes goes on:

• "Toggle Overlays" keeps reenabling itself after every turn, even if you turned them off due to visibility hindrance.
• Right-clicking on tiles and doors is finicky and inconsistent with the mouse.
• Marines' inability to shoot an enemy is the exact same set of speech bubbles, regardless of whether they are out of ammo or whether the enemy is out of range, so you could never actually tell how far their range is.
• Audio balance and quality is inconsistent; monster "hurt" sounds are disproportionately loud alongside gunfire, and lack the echo that other sound effects have, really jarring oneself out of immersion in the game.

I will update this review if any of these factors is addressed, but I can't recommend this to anyone in its current state.

Hi, Keron.

no overwatch/guarding system like in the first Steam Marines, so if an enemy was spotted around a corner with not quite enough action points to reach and deal damage to it on any significant level, there is nothing you could do but flee or sit still, and maybe guard if you have four APs left.

SM2 is designed quite a bit differently from SM1, which is why there is no Guard mode similar to the first game. Guard mode confers a defensive bonus in SM2 instead because of how marine skills, the levels generated, and how enemies will approach the player differ from the first game.

no way I could see to turn your soldiers without taking a step forward, so you literally can't turn them around to face the other way if you have two APs left.

There's no turning because (unit) facing does not matter for gameplay mechanics in SM2. SM1 had cardinal direction facing with cone of sight for fog of war and you could only fire in one direction at a time. In SM2 you can fire in all directions from any tile position.

nothing that told you that reloading is done automatically between turns.

I'm not precisely sure what this means but marines don't reload their weapons. There are enemies that will have random events that can include them taking the turn off to reload their weapons, though.

Marines' inability to shoot an enemy is the exact same set of speech bubbles, regardless of whether they are out of ammo or whether the enemy is out of range, so you could never actually tell how far their range is.

I'll need to double check this but this shouldn't happen because only older versions of SM2 prevented marines from firing when the ammo counter hits 0, or you don't have enough ammo to fire that marine's particular weapon. In later versions having low ammo simply confers a hit chance penalty. It could be that there is an out of ammo message in a wrong dialogue pool, but it shouldn't show in a dialogue popup since there are no dialogue popups for enemies you can't actually target. I could be misunderstanding your comment.

no list of keyboard shortcuts anywhere, whether in the game, a manual, or on the websiite

From the main menu: Setup > Keybinding. A lot of tooltips also have keybinds in them. If you're turning off the overlays then you won't see them.

"Toggle Overlays" keeps reenabling itself after every turn, even if you turned them off due to visibility hindrance.

I thought I killed this bug but maybe I didn't. I'll look into it again.

Right-clicking on tiles and doors is finicky and inconsistent with the mouse.

I don't think I've had reports of hotspot issues but for floor tiles specifically they will change color when the cursor is detected over them. If overlays are on you will also see tooltips for floor tiles and doors that will indicate if you can actually interact with them at that cursor position.