Very very clever idea, fits well with the theme! Levels without the needing to collect the gems are very easy, so I would make them obligatory. Also, asset selection is also pretty nice. Overall, solid entry!

Here we have a really good game. What I like: The art, audio (I know you didn't make them, but that doesn't change the result. Obviously it would be cooler/better if you made them too^^).  Game design is great. With the layout you made the player has really to use the rewind mechanic (+ to dodge things). Character Movement(+ mechanics) feels good, all in all a good entry!

Interesting concept but I found myself waiting around which disrupted the flow. Overall a good game :) 

Good gameplay and nice graphics and visual effects to support it, I liked the rewind mechanic on this one, makes great puzzles

I'm impressed with the gameplay and game design of this one. The rewind mechanic is very interesting, with the added visual effect of the previous positions, which I love. It forces you to reach the objective with 'clean' paths so when rewinding you know what comes next, using it to dodge obstacles. The audio and art chosen match very well. Overall great game, with an interesting and enjoyable mechanic.

Its a great platformer, I love your mechanic of rewinding. the level design is great.

I loved that there is a level select menu, the options menu works well and the colliders are excellent, I didnt have any issue.

I got every red gem :D

overal, A Very Cool Game ;) 

Played through your game in this video here at 01:01:20

Cool little game! The mechanics are pretty interesting. I like how theres a shadow/ onion skin of the player every few frames and how the controls are pretty smooth. The graphics and audio are aesthetically pleasing and well done! However, some suggestions would be to add a little backstory to make the game more juicy. Or maybe some more content other than gems, moving enemies and shooting thingys. Other than that, its a pretty great game! It has a lot of potential too, coming from a one week game jam!

awesome use of rewind and well made art but:

rewinding makes it hard because its slow

trail sprites are too annoying 

levels are hard from the start

i don't think many people know what is backspace, i literally googled it

good game after all

Loved it, the theme executed perfectly and the levels are very fun and the gems give that extra challenge that every completist would love

Nice game design right there, gems are really well executed(even if there is no reason to get them hahaha) but it is a nice touch on the final game! Audio is really good too, puzzles are hard(I'm okay with this, maybe others won't) and really makes you be careful when rewinding. In my opinion is no hidden gem or anything perfect, but it is a nice idea, with nice execution and I liked it! Congrats!

Be sure to check my game too!

Like the consept, and the visuals are great, I especially liked the trail, although I think the rewind is a bit too slow

finished the game, 2nd level imo was harder than the last. each level is basically two with the rewind feature, very cool. The afterimages are helpful to show the future position during rewind

To leave a trace of shadows of previous movements is brilliant! I really liked the rewind feature on this one, pausing while rewind is a gamechanger. That one was very fun to play.

I wished that it this game should be longer when I completed it, I deeply enjoyed that one. Please let me know if you publish a complete version of it after the jam, I look forward to play it more.

Really cool concept, and actually quite difficult if you're impatient or a wannabe speedrunner like me lol. I kept dying to the lasers on the second level.

I also used trail rendering in my game! It's finicky and I had to end up making my own script for it but I am impressed with how yours works.

Nice job!

The game is fun to play!

Th theme is hit on point! The trail the player left behind was a very good idea, so that you can keep track of the path you took. Maybe a "hardmode" without the trail would be interesting"

Here's my honest opinion:
-It's a cool looking pixel game!
-At first I thought there would be some hack and slash action, maybe that would be a nice addition.
-Though the rewind mechanic fits the theme very well, I find it needless to go to the lever to just return back to the start door (especially if the player forgot or choose not to pick up the gem.)
So maybe an incentive to go there would be great. Or probably redesign on how to use the rewind where it would make most sense.

I hope this helps to make it better, because you already did a good job on the rewinding and visuals.
So keep up the good work!

Very fun take on a rewinding platformer game! I felt it was a bit easy to be able to completely control your rewind you could basically just do the same things but reverse. Maybe something to force the player to think differently would be nice. Otherwise love everything about this game. Well done!

Really like it! I usually give really detailed feedback, but I honestly don't know what I would recommend to improve in this game! I think it does what it sets out to do very well!

Things I liked:

>Simple game premise that was executed well

>Fits the theme perfectly

>Graphics and Audio are very nice and stylish and fit the game well. Well utilised.

Things to improve:

>Hmmm, I guess a couple more levels would be nice :) (that means I liked it haha)

>I think there was a point on the 5th level where the rewind got a bit out of sync with the images it was getting rid of (as in the memory images of the character were disappearing before the character was rewinding up to that point; maybe cause I did a big jump from the top platform with the gem down to the middle platform). Was only a very minor issue, didn't really affect me too much; but I imagine it might bother me if the level was longer and the sync issue got bigger (but i didnt notice it on any other level). 

>A harder mode would be cool (you could make it so that the rewind happens slowly whether you like it or not, and you are just in control of whether to speed up the rewind or not?). I found the rewinding aspect to often be easier than the first run (provided I didn't confuse myself by doing lots of unnecessary movement on the first run through) because I could freeze my character mid-air to wait for obstacles to pass (something you cant do on the normal run through). So perhaps having a harder mode would ensure the rewind runthrough is as challenging as the first run through.

Overall:

Great game! Really enjoyed it!

I really like it. the visuals are so god. well done!