The majority of the game is flying through levels with the jumping dash attack. Timing your dash with when the assault rifle guys shoot at you propels you with an extra speed boost in the direction you are traveling. All other enemies will typically knock you backward and should be avoided. To get the most height on a jump you jump once, dash, jump again, dash. You need to land on floor or wall to reset jumps and dashes. Mouse and keyboard is highly recommended for boss battle aiming efficiency and rocket jumps and skill tree efficiency.
The biggest hurdle for completing the worlds quickly is the lengthy boss battles. Proper weapons are required for a good run. All weapons have a damage roll and can have additional modifiers. Weapons may have 2 regular modifiers and 1 keystone modifier. From my testing, the only regular modifiers worth using for damage are In Flight Meal (+50% damage while jumping), Crunchy (+30% damage), and Crispy (+20% damage). The only Keystone modifier I have found useful is Scavengers Assemble (drops ammo for the one weapon during boss fights), but it's worth testing them again (the ones that sounded good didn't work as intended in my tests). The added damage modifiers do increase the base weapon damage noted on the weapon except for In Flight Meal, which both doesn't add to the base damage and doesn't work against many bosses. Upgrading a weapon requires proper resource management as it costs Calories, Protein, and Fat. Collect Protein up to the 7500 cap to gain calories as well. When not upgrading soon, collect a Syringe (resets fat and protein) to clear your protein count so that you can get more protein>calories. A note on upgrading; if you spam to upgrade instead of waiting between each selection, it will double/triple the resource cost (bug) and you will have no calories. The current iteration of weapons used is below:
A-Salt-Rifle: base damage roll variation somewhere between 4.5 and 5.5. Add In Flight Meal at Level 3. Ideally collect a Syringe afterward if one spawns. Ideally the Salt Rifle has a high damage roll and includes a +30% or a +50% so that you can have both for the boss. Use a combination of jumping AR, AR secondary, and jumping shotgun to kill the boss. If boss is in a lower animation when it dies, you can skip the dialogues after.
Shroomstick: ideally a good damage roll with In Flight Meal, but is only really used (for damage) on boss 1 and isn't that important. Just grab one and go.
Flambe Torch: ~4.5-5.5. Add Crunchy and Crispy during world 2. (bosses 2-4 appear to not accept the In Flight Meal mod). There are many resources and flambes on the 4th stage so it's ok to take syringes or miss weapons until then (upgrade station at bottom of stage 5). Good to take syringe after you are good on upgrading or during world 3 early on.
Critter Cannon: base damage variation somewhere between 29-33.x (maybe higher). Add Crunchy and either Crispy or In Flight Meal (I choose Crispy). Boss 5 does accept the In Flight Meal mod. You CAN upgrade during world 3 if your resources are good. It does appear to speed up phase 2 of boss 3 if you alternate flame and critter. With this gun and guns following, do not spam ammo on bosses; try to time shots for when the boss becomes vulnerable again after each shot. Use primarily this gun on bosses 4, 5, and 6.
Meat Seeking Missile Launcher: 50-65 roll? I only worry about getting the perks on it that increase capacity by 100% and 50%. This takes the ammo count from 10 to 30. It's also fine if you get the one that regenerates 1 ammo every 5 seconds instead of the 50% increase one. The main purpose of this weapon is to rocket jump through stages from world 4-8 as efficiently as you can, but you can try to reroll the damage before doing upgrades if you want. It is used a bit on bosses 4 and 6. Remember to manage your ammo count after every stage as noted later.
Buffet Launcher: The big boy. This is your boss destroyer. ~45-55 roll? Bosses 7, 8, and the final fight will all be melted. You want Scavenger Assemble keystone for sure to give 4-ammo packs during the fights. This requires extra calories, fat, and protein. Crunchy is very good. And then you must choose between In Flight Meal and Crispy for the final slot. I currently take In Flight Meal, but it's certainly debatable; Bosses 7-8 do not react to the +50% modifier, but many of the final Vora fight iterations do (main one that repeats and bird are all that come to mind). Remember to manage your ammo count between boss 8 and the Vora fight.
Skill Tree. Remember many items on the skill trees cost calories per second. It appears viable to use either the Robot-eating tree or the Meat tree. For the meat tree you only go down and take a point in the Protein adds damage mod (the upgrades cost lots of calories so you may want to wait on some of those until later). For the Robot tree, you want what is on the far right column which gives you 1 ammo anytime you take damage. This is good mostly for keeping Rocket ammo high when you rocket jump through stages. You can also take damage during phases of the final boss to refill ammo. There is the bottom left mod which is optional. It allows you to damage yourself with your shield to refill ammo if you have both perks but it does a lot of damage. Mostly good at end of stages to make sure you have the proper ammo count (especially rockets at 50% capacity). The mid-right allows you to double your shooting speed every 10 seconds which can be faster on early boss fights, but is not currently possible (I don't think) to use on those early fights because the skill tree always bugs then you can't get the bottom right node afterward as early as you need (have to take the left long way after). Also later on regardless of choice of Tree, take the top tree to add HP if desired and the convert calories to damage mod (remember this also costs calories per second for your run). It is possible to experiment with Zombro mods (i.e. the meat tree) since you do move faster but I didn't find it to be great in my tests.
Ammo refills. Ammo can be refilled by swapping weapons or rarely picking up the ammo boxes from enemies. However, the primary way of refilling ammo is from stage transitions. It appears loading into a stage doubles your ammo count. Thus you never want to completely run out of ammo (for most weapons like critter cannon, keep a couple during boss fights so that it's full by the next boss - for rockets, always try to keep them at or around 50% when ending any stage).
Optional Teleporters - It's possible some have changed during game update iterations that I missed, but the current ones that I note save time are stages 1-3 saves many seconds, 2-3 (on bottom where you slightly backtrack) saves like 1 second RTA, 6-1 under the start is about the same RTA speed compared to going normal efficiently (without rocket jumps), 8-5 saves many seconds.
Random Teleporters - generally not advised for optimal run, but the random yellow ones can give you fat and protein if you need it for an upgrade; will cost you close to 10 seconds. It may be possible to go in the random teleporters that take you to the gambler to get an early Buffet Launcher, but I have been unable to obtain it early in my tests. Costs a lot of time but would be worth it if you get early enough in the game (these teleporters appear to currently start appearing in world 4 for sure (maybe 3?).
Good luck. Joe
