1. The cool down felt really frustrating to me. It is a little hard to correctly grapple into the wall and if you mis-click then you aren't able to use the grapple hook again and this often means losing. It made the game harder, but it didn't seem like a fair way to die. It also was difficult to tell it was a cool-down. It just felt like the grapple hook wasn't working. Having some sort of cool-down UI element might help with that so the player knows when they can use the grapple hook again. As a side note, it also might help if the mouse shows where the player can click to get the grapple hook to "stick" to the wall. This could be shown with a circle around the mouse- red means the grapple hook won't stick to the wall and green means that the grapple hook will stick to the wall.
2. I think having a number with a visual to show how far the lava is would be a nice way of showing its position relative to the player. Maybe have the distance listed at the bottom and once it reaches a certain distance away from the player you could have some sort of visual effect (like a red glow on the edge of the screen that gets more intense/brighter when the lava is close- like how Leviathan does it) to warn the player that it is close. You could also look into having camera effects (like shaking) or particle effects for when the lava is getting close.
3. Unless there is an in-game reason why the cool-down time period changes, I think it wouldn't make much sense and would feel unfair to change it randomly in the game. If you wanted to change the cool-down rate you could have faux "levels" to the game. This could be pre-determined checkpoints that the player reaches that you can use to change the lava/player speed. For example, after the player reaches 100 in game meters then you can change the values for the speed of the lava, cool-down time, and the player speed. For this to work without feeling random, you can display that they have reached a new checkpoint/level and have some visual to make the game feel like they are in a new/harder level. Alternatively, you can have pick-ups or have areas that the player has to go through (like how racing games have a boost area- attached is a picture from Crash Team Racing Nitro to show what I mean) to either increase the player speed or reduce the cool downs for the grappling hook. You can have the collectibles/areas be more frequent later in the game to balance out the lava. Alternatively, you can have the player collect something to give them the ability to slow down the lava. Maybe it could be like a "freeze time" ability.
Overall, you all have improved the game a lot since the last play test. Great job! I love the player animations, the lava, and how the game is coming together. I look forward to seeing the final product.
-Breanna Flickinger
