I'm liking the hit and run (or jump, rather) combat, but I'm not liking the platforming part. I think you'd need to have smooth and more easily controllable jumping mechanics to make that enjoyable, but we'll see how it works out with the changes you're making.
A few UI suggestions:
- the health indicators / energy bar are too big, scale them down a bit
- when you use an item from the inventory, don't show the message box that requires pressing X again unless it applies a newly discovered effect
- show the health pack count in the hud
- create a hotkey for health pack usage
Found a bug too: if you move and jump through the transition, you'll have to repress the movement key
Overall, I think the game has a nice feel to it. Looking forward to the full version.