Like everyone else, I'm a fan of the art and music. The first time I saw the cat in the mech was WOW. More games with cats please.
In case it's useful to you on this or future projects, here's a few level design tips I've picked up from industry professionals:
- Composition: stick to the same rules of art composition so the level is visually pleasing
- Guidance: use light, leading lines, pickups/rewards/collectibles, locks (interesting things the player cannot get past) leading lines, and weenies (large or extremely visually distinct objects) to guide the player through the experience
- A-B Encounter Design: introduce one enemy at a time so the player can get familiar with them, then you can start pairing after they're familiar. Enemies that pair together in interesting ways that force interesting choices, tradeoffs, or new ways of playing keep the experience fresh throughout.
- Difficulty Curves: basic AAA challenge structure (which works really well and feels great to players) is easy-easy-medium, followed by easy-easy-hard. This lets people feel good about themselves, but applies pressure over time and as their skills ramp.
- Verticality: use varying heights to mix up the experience and alter power levels.
If you improve your levels, you could really do some amazing stuff.