itch.io

Thank you for playing and well done getting that far! 

I think you have given some really good feedback and I'll try my best to answer your points in order:

1. The new abilities gained, such as when equipping a new weapon, are automatically added to the hotbar (and removed if lost). You are then free to move them around and change what abilities are on which page.  If you open the abilities panel (hotkey K) you will get an overview of all the abilities you have access to and can drag them to wherever you want.
That being said, having the option to 'lock' the hotbar could be useful, or at least not auto add new abilities, perhaps as a game setting or a checkbox right by the hotbar. Thanks for the idea!

2. You can switch hotbar in any direction (with wrap-around), resulting in what you saw if you go in a negative direction. If you use the up-button instead you will switch it in a positive direction.

3. You seem to have encountered our system of enemy reinforcements, put in place to give the player a sense of urgency and to discourage players from loitering. Each simulation tick, there is an ever increasing risk of increasingly difficult enemies being spawned and sent to hunt you. The risk being reset when you encounter new ordinary enemies. Your best bet to avoid them is keep moving ahead towards the next floor. We decided to use this mechanic instead of having a limited amount of food, fuel or similar resources to manage, which is often used to keep the player moving forward. 

4. Good point on the difficulty, we actually lowered that one quite a bit before launch since many testers kept dying, and dying, and dying . Perhaps we need to turn it up a little again in a future patch.
Please let us know if you got as far on the next run if you decide to give it another go.