There should either be a hot key for upgrading, or set up an upgrading system such that the player can set which type of tower they would most prefer to upgrade first, along tower level preference (upgrade higher level towers first, or lower level), then the second type of tower preferred in the upgrade chain, and then finally press a key to apply one's gold towards upgrading their towers (as much that can be applied towards upgrades as possible).
The boxes are actually your friend in this game, since if you hit a box, your next jump is not going to be smaller, but the following one will. In other words, the boxes help to slow down the game and keep you running longer. I got to 5000+ easily by hitting a box every now and then.
For the sixth competition:
Part 1:
||R|2,3,-143,0||447,124,145,124,185,231,p,141,202,235,26,683,397,125,185,140,142,p,183,106,83,28,243,360,145,98,178,233,p,102,198,252,23,173,98,112,157,132,106,p,171,107,58,18|668.9|324.6|673|209||
Part 2:
||R|2,0,110,0||192,379,100,196,53,166,p,164,62,184,7,90,143,100,36,133,152,p,0,0,0,3,403,189,100,21,103,181,p,0,85,170,12,380,371,145,49,154,70,p,0,99,0,20,552,467,100,231,100,7,p,0,0,0,5|460.95|173.45|417|84||
Part 3:
||R|2,1,41,0||62,76,100,58,127,183,p,59,133,170,23,492,415,121,106,176,0,p,167,195,90,22,349,176,186,0,0,0,s,0,0,0,0,141,377,145,37,132,185,p,0,0,0,2|62|15.95|100|141||
Part 4:
||R|2,3,30,0||437,118,100,166,118,68,p,93,0,0,3,267,85,112.5,234,84,200,p,221,90,255,27,555,405,129,195,137,54,p,0,0,0,1,118,411,120.5,92,194,150,p,65,195,104,49,283,293,100,116,100,209,p,113,68,212,26|326.55|54.6|218|61||
For those stuck on level 23, this shot I took has some promise to it:
||R||p,577,309,1,0,p,494,110,1,0,p,489,57,1,0,p,452,15,1,0,p,406,-9,1,0,p,130,409,1,0,p,178,436,1,0,p,513,435,1,0,p,555,398,1,0,p,574,350,1,0,p,104,372,1,0,p,89,330,1,0|191,329,100,109,0,14,p,130,0,0,29,443,345,113,52,90,115,p,0,0,0,4,367,118,100,39,142,13,p,0,113,25,26|226.25|280.45|286|321||
First part of level 11 competition:
||R|2,2,132,0||482,419,100,69,81,92,p,39,39,39,49,301,252,145,217,152,228,p,221,184,229,39,131,93,111.5,208,87,38,p,206,104,76,41|540.45|405.5|517|311||
Second part:
||R|2,1,175,0||613,224,100,160,66,54,p,190,87,45,16,111,266,100,115,178,89,p,100,160,80,11,370,396,145,203,160,80,p,190,170,65,12,325,73,145,81,106,203,p,0,0,0,3|613|164|615|281||
Third Part:
||R|2,0,-23,0||620,107,100,150,20,244,p,141,16,235,22,521,393,125.5o,85,108,129,p,85,93,138,12,129,405,137.5,243,160,80,p,255,195,65,15,326,107,145,157,20,203,p,0,0,0,6|102.75|328.75|162|448||
Try to copy these for an easy plat on the competition.
 "Incremancer"){kind=icon}
 "Cardinal Chains"){kind=icon}
 "Cursed Treasure: Level Pack!"){kind=icon}
 "mini Tower Defence (mTD)"){kind=icon}
 "Chibi Knight"){kind=icon}
 "Ether War"){kind=icon}
 "Dead Drunk 1.2"){kind=icon}
 "Canabalt"){kind=icon}
 "Gateway I"){kind=icon}
 "Gravitee 2"){kind=icon}
 "Hero's Arms"){kind=icon}